I put hidden and obvious lines of code in my models that do not effect the model but If a dispute ever arose I could pretty much prove that its my model. besides everthing I have offered is free and if you read the read me I don't care how you use it. If its for sale Zip it up with a password and change it every so often. That way only legit people who buy it can get the password. Not by any means foolproof but will tend to frustrate the people stealing your stuff.