I thought about stealing some of this code but I stopped when I saw the copyright notice
Am I then in violation?
You’re good!
I’m a big fan, and I use it a lot.
Not quite. The FSF says it's GPL compatible, but they do not recommend it:
> This is a lax permissive non-copyleft free software license, compatible with the GNU GPL.
> We do not recommend this license. If you want a lax permissive license for a small program, we recommend the X11 license. A larger program usually ought to be copyleft; but if you are set on using a lax permissive license for one, we recommend the Apache 2.0 license since it protects users from patent treachery.
Source: https://www.gnu.org/licenses/license-list.en.html#WTFPL