isn't that illegal is some countries? also that would create a legit reason for banks to go against bitcoin (IMO).
better not do that.
Lol, I doubt banks are going to 'go after bitcoin' because people are defacing notes. I guess it might be ilegal to write on some countries notes but 1 you're very unlikely to get caught or prosecuted and 2, banks and shops write on banknotes all the time in my country so probably not illegal. I think it wouldn't be a bad idea but I wouldn't do it. Maybe just stenciling a bitcoin
BTC would pique peoples interest though.