Many magazines (in the United States, anyway) today find the main profitability is in having higher subscriber numbers to show advertisers and really don't care if the subscriber is paying. The main reason they require payment is to satisfy the Postal Regulations for 2nd class mail (which ensures timely delivery at a reduced cost). (Source - I worked for one, once.)
Given that, if someone has a magazine subscription that they let lapse, but the magazine keeps sending them, is he or she obligated to proactively inform them to stop mailing the magazine? And if so, how far do they have to go to get it to stop?
To avoid some potential leniency, please assume in this case the magazine owner is Jewish.