Kalashnikover_Rebbe at hashkafah.com asked:

Isn't blocking ads stealing? The people put them on the sites for a reason.

He elaborated:

On one hand, the argument can be made that [forum XYZ] is publicly broadcast and distributed, and what you do with it once it hits your PC is your own business.

But an argument can be made that the service is provided on the implicit tanai that you at least view the ads — as well as the more general and abstract concern that, if everyone started blocking ads, advertisers would stop paying to place them ... It would be bad for everyone, because so many sites are kept alive by ad revenue ...

The fact that it's smut, though, is irrelevant. No one forces you to come to view and participate in [forum XYZ] to begin with. And, if that is how the site administration chooses to raise funds, it is their choice. You can take it or leave it ...

The real question is: can they make such a tanai?

So — is ad-blocker software permissible? Please cite your sources as best as you can remember.

(Note to readers: But, in the end, ask your rabbi.)


Another interesting point: The big ad networks have been used as vectors to spread malicious software on quite a few occasions.

  • 5
    Can you ask someone to clip out all the ads from a newspaper/magazine before you read it?
    – HodofHod
    Commented Feb 17, 2012 at 19:55
  • 3
    Not an answer because no source, but how is it any different than ads on the bus (subway, etc.)? The same implicit assumption applies there too, but I highly doubt that there is any halachic or secular legal argument that you must look at the ads.
    – Alex
    Commented Feb 17, 2012 at 19:58
  • 2
    @Alex It's not comparable to you not looking at the ads on the subway - it's comparable to some frum zealots placing black curtains over the ads on the subway, as the train passes through their frum neighborhoods.
    – user1095
    Commented Feb 19, 2012 at 8:21
  • 3
    Ads on the internet, are a completely different ball of wax than ads anywhere else in the world. They really aren't very compariable to much of anything, and they work on completely different premises.
    – avi
    Commented Feb 19, 2012 at 9:09
  • 3
    @Will: how so? I'm choosing to close my eyes to the ads, and I'm choosing to install the ad blocking software. No third-party "zealots" need be involved in either case.
    – Alex
    Commented Feb 19, 2012 at 15:05

3 Answers 3


I asked my local Haredi Orthodox rabbi. He said that ad-blocking software is permissible to use. He added that, even if it's hard for webmasters to detect and work around ad blockers, that's no problem for me. Some things in life are hard.

My rabbi said it was fine for me to post his ruling online. But he asked me not to mention his name here: he doesn't want angry web marketers complaining to him about the ruling. :)

  • Whether it is hard to detect or work around adblockers is not the question. And who cares about that!? The problem is causing other people to sin, and being deceitful. It seems your Rabbi is not aware of that aspect of the question. But if people have no problem being the cause of others cheating and lieing and stealing, then Gzunt Gheit
    – avi
    Commented Feb 26, 2012 at 9:56
  • @unforgettableid to be intellectually honest about it, you would have to print out Avi's answer, show it to your rav, and THEN ask if ad-blocking software is still permissible. (I think it is, but Avi raises concerns that most people don't take into consideration).
    – user1095
    Commented Feb 26, 2012 at 12:59

First of all, people who produce ads are surely aware of the existence of ad-blocking software. They therefore expect that a certain segment of the population will not see their ads. Secondly, civil law allows the existence of ad-blocking and does not consider it stealing. Dina d'malchusa dina.

  • 6
    As someone who worked in the industry, this is not true. The problem is that it is not enforceable. Secondly, if Jewish law says that something IS stealing, but civil law says that it is not stealing, you are NOT allowed to take the item.
    – avi
    Commented Feb 19, 2012 at 8:35
  • 4
    @avi, what part of the answer "is not true"?
    – msh210
    Commented Feb 19, 2012 at 15:13
  • 1
    @avi, there are many ways a website could block ad-blockers. for example, it could have add some simple code that only displays the content if the ad is displayed. (this might eventually lead to ad-blocker-blocker-blockers, but would work in the meantime).
    – Ariel K
    Commented Feb 26, 2012 at 6:07
  • btw, note that the latest version of adblock plus does allow certain ads by default.
    – Ariel K
    Commented Feb 26, 2012 at 6:07
  • @msh210 There is no expectation that a certain percentage of the population will not see their ads, because "seeing" ads is not part of the calculation. The ratio of ads served to ads clicked is what is important. There is an assumption that ad blockers prevent ads served completely (which is not always true either, but it's the working assumption)
    – avi
    Commented Feb 26, 2012 at 9:39

The problem here is that Kalashnikover_Rebbe doesn't understand how ad blocking software works, nor how online advertising works. You cannot compare online advertising to offline advertising. They might have the same purpose, and the same name, but they are completely different things.

First, online ads are measured in "Clicks" as well as "Eyeballs".

Advertising in general in the non-interactive sphere, works on statistical models and general usage, and a lot of unknown information. Online advertising works because of precise, recorded, and individualized information. The main difference between advertising on a billboard or TV or Radio, is that the information only flows in one direction. Advertisement to person. But on the internet, information flows in two directions. The ads and the person being advertised to, interact with each other. It's more like walking into a store and engaging with a sales person, than it is viewing an ad.

There is a large "pipeline" of the way advertising works on the internet.

First, you have the ad agency, which creates the ad. Some company hires an ad agency to create an ad. The ad agency is then given a budget of how much they can pay various websites to display the ad. This part of the contract is never affected by ad blockers or the like.

The next step is that the ad agency (or an ad aggregator such as Google or DoubleClick) sets up a deal with various websites. This deal depends on where the ads are shown, how popular the website is, et cetera. Here, a term is used to measure the effectiveness of the ad. CPM (Clicks per M (either thousand or Million)) Meaning the Ad Agency tells website X, that I will give you $1.00 for every thousand people who click on the ad. Using various other metrics, a website might argue that their users are more prone to click and then purchase an item than other websites and might demand a $5.00 CPM or a website might have completely random ads and only be offered $0.25 CPM. This part of the contract and process is highly affected by ad blockers.

There are two types of ad blockers.

  1. The ad blocker stops the ad from being retrieved from the server in the first place.
  2. The ad blocker lets the ad be retrieved from the server, but then hides it, making it invisible to the user.

Each of those types of ad blockers affects, a different person in the chain, and is potentially stealing from different parties.

The first type of ad blocker, creates a discrepancy, between the statistics of the ad company and the statistics of the website which gets paid for the ads. The ad company will see that only 10,000 ads were "viewed"; and, of those 10,000 views, 100 people clicked. However, the website owner will see that page was viewed 50,000 times, but only 100 people clicked. If the website company is honest, this will greatly hurt the relationship between the ad agency and the website. So, in this case, this ad blocker, may not be 'stealing', but it is definitely "putting a stumbling block", causing the website owner to lie and be dishonest with the ad agency company. Because they will use the 50,000 views number when setting up the initial CPM, but will be getting paid based on the 10,000 number giving them more money. In other words, by using the ad blocker in this scenario, you are effectively making it very hard for the Website company to resist using "false weights and measures". I know this, because I had to quit a job over this issue. The pressure was just too high, to not be false about what was happening. The ad agency wanted to "dump" ads from their budget in X amount of time, and the hosting websites wanted to make more money. There was no incentive for any individual party to be honest. (Very similar to what happened in the mortgage scandals)

The second type of ad blocker, gives the ad agency, and the website the same statistics. However, those statistics are wrong, and nobody will know why. Everybody will think that 50,000 views are being seen, and that the ads are viewed 50,000 times, but only 100 people click. They will assume then, that the ads are placed in the wrong part of the page, or the wrong type of ads are being displayed. But the reality, is that they are getting 10,000 views of the ad, and 100 clicks. (Which is the expected rate). This means the website company will spend many days and hours and time trying to "improve their Click rate". Here you are stealing with geneivat daat. I can not tell you the number of hours and days and stress and even one UX expert losing their job, because they insisted the Ads were placed in the best place possible, but data was not showing improved results. I do not know if that was because of ad blockers, poorly chosen ads, or just a bad audience. But, if it was because of ad blockers, nobody would be able to know, and the assumption is that it's the designer's fault for not getting more clicks.

The fact that ad blockers are not enforceable to legislate against, or that people demand freedom of their computer screens and so nobody would be willing to legislate against them, doesn't remove the fact that they can in theory cause serious harm and damages to people who's lives and livelihoods depend on those ads being displayed and recorded accurately.

  • 6
    Great answer, in that it is very thorough. However, no +1 because I don't see how any of this is the end-users concern. To take an example from the previous generation, it would be like saying that using your VCR to record a program, and stop recording during the commercials, is stealing. You never signed an agreement with the TV station. They are providing the stream of data (in this case, video and sound) to you for free. They hope that you will watch the ads, but one does not obligate himself to watch the ads simply by watching, or even recording, the program.
    – user1095
    Commented Feb 19, 2012 at 11:18
  • 4
    "The first type of ad blocker, creates a discrepancy, between the Statistics of the Ad company and the Statistics of the Website who gets paid for the ads. The Ad Company will see that only 10,000 ads were "viewed", and of those 10,000 views 100 people clicked. However, the Website owner will see that page was viewed 50,000, but only 100 people clicked. If the website company is honest, this will greatly hurt the relationship between the Ad agency and the website." Nah, everyone knows about adblockers, and site owners trust OpenX's or Doubleclick's or whoever's numbers. Same with the 2nd type.
    – msh210
    Commented Feb 19, 2012 at 15:18
  • 9
    You've done a great presentation, avi, of the problems that the use of ad-blockers can cause on the 'supply' end of the ads. However, just because a certain method of consumption breaks someone's business model doesn't necessarily mean it's illegal, unethical, or non-halachic. Would you say, for example, that I'm not allowed to put sticky notes on the part of my display where banner ads usually appear? There is absolutely no conceptual difference between that and ad blocking, except that the latter automates the process.
    – Dave
    Commented Feb 19, 2012 at 15:38
  • 3
    @Dave ...Or turn off image-loading in the browser settings. Or get a text-only browser.
    – HodofHod
    Commented Feb 20, 2012 at 2:57
  • 4
    You completely ignore the fact that the general ad delivery services are vectors for security attacks, that the big ad distribution companies know this and don't care, and thus the ads are actively harmful.
    – Yishai
    Commented May 6, 2014 at 22:15

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