I don't have the book myself, but I believe it is called To Touch Kindle a Soul, on chinuch. It contains, in the endnotes a reference to a letter written by Rav Moshe Feinstein zt'l, Rav Shach zt'l, ...
What is the problem with shaking one of the no battery/shaking flashlights which is on on shabbos?
My neighbor has never set up password protection on his wireless router. If I wanted, I could wirelessly connect to his high-speed Internet service. May I use his Internet service without asking him ...
Do photocopied sheets (such as chumash or gemara) need to be put in sheimos or can they be thrown straight into the garbage?
If I'm running a small minyan that sometimes has a quorum and sometimes doesn't, and I'd like to only hold the minyan when I know we'll have ten, is there an online tool to help me manage this?