7bit wrote:[...] Also, even if it is OK to use these, a source would be nice.
See the difference between those?
The left version (which I never use) does not show where the smiley comes from, although it can be obtained with one right mouse-click on the author's site.
The version on the right shows where the smiley comes from (when pointing on it with your mouse), and it is explicitly made available by the author for use in forums ("click on the smiley and copy the code"). Of course I wouldn't use them if it weren't so.