I left my modified cards around for people to find.
What is your reason for leaving modified cards out?
A stranger could pick them up and also get addicted to them.
Modifying cards and leaving them out so that other people use them and get addicted is improper. Cards should be left alone in their original condition.
I don't follow your rules, I make my own.
Just try to think about others before leaving your modified cards around. While I am not an expert on these, I do know that it would be much better to keep from modifying them for the sake of others.