I don't know about requiring a tip, but a while ago I pointed out (it's somewhere in the forums) that we are actually using icons and not including their license agreement with them, which is in violation of it (the icons are from Sun).
If someone is actually going to do something about icons, they should either take the time and import the license agreement (along with the other icons which for some reason were not imported from the same package) or replace all icons with a new set...
