i agree with shabbir,
(saying it personally) there are few sites i haveily use (for downloads and all),
but i am nt able to donate to them, first being a student, second safety reasons(online frauds), but then i never felt donate button shouldn't be there....infact i feel whenever i be in a position to donate, i'll first donate to them as these are the sites that have helped me gain knowledge.
So even if i feel bad, its somewhere for the good....