I used to donate five dollar per month for different free and open source software or foundations, I've given numerous such five dollars to Mozilla. However, Mozilla project is dead to me now. Firefox is getting objectively worse (XUL removal, Pocket etc.) and the Mozilla project lost when they carve into the bullies when the CEO was forced to resign for some random donations. I don't if you donate to Hitler, it's his personal money, what do you care. Mozilla cannot champion the open web. The open web is dead.
Instead donate to OpenBSD or FSF.