Any code I make for clients is under a strict license unless specified otherwise. It's a straight forward license pretty much stating that they can't sell it or claim it as their own. I've had a few clients break that license but one stood out. I had made a piece of software that cost her over $2,500 due to the amount of hours that went into it. The transaction went along smoothly so there was nothing to be alarmed about. She came back for more work about 6 months later and I decided to do some checking up on her to see how her business was going. Immediately smack bang on the home page was my software being sold for $30/month. Needless to say I was outraged. She said there was no talk of a license which I responded with pulling out the contract that she signed where it explained that signing the contract meant she was in agreement with the specified license. 2 months after this started, I'm being awarded any profits made from said software along with her closing down the website. As much of a bitch as she was, it wasn't worth my time trying to get more out of her.