A prof I had back in college does a bit of contract work on the side. She learned a trick early on that she employs in every job she does -- self-destruct code. Unbeknownst to the client, she puts a backdoor in every program she ships that enables her to pull the plug. She used it to ensure that they didn't stiff her on the bill, but a similar strategy could be used in your case. If you don't like the way they're using it, activate the self-destruct code.

I'm not sure of the legality of that technique, though. It seems that as long as you own the code and they're just licensing it from you, then you can make the code work however you want, including making it not work at all. But I'm not a lawyer, and don't even play one on TV.

Still, it's something to consider. If they're willing to rip you off like that, they're probably just as willing to walk all over any license you make them sign. Adding a self-destruct would put enough power in your hands to resolve difficulties like this.

But it sure would suck if they *were* a nice company, and the self-destruct got found out by someone else...

Update: Upvote! Downvote! Upvote! Downvote! Ah, sweet controversy.

Like I said, I don't know if this is legal. Probably there's different ways to implement both the code and the accompanying license, some ways will be legal, some ways won't. The idea is not without precedent, though. Take a look at this bastion of legality and moral uprightness.

Ethically, it's a grey area. It's somewhat akin to carrying a concealed weapon. Some will pack heat for protection, others will use it to rob banks. Implementing self-destruct code gives the programmer a considerable measure of power over the client, and that power could certainly be abused.

But is it morally right to exercise such power in a case like this? (not "legal" -- "right") I'll leave that question open. :)

As for implementation, it needn't be a complete erasure of the code. Simply making it not work, or even slowing it down considerably, would suffice. Perhaps make it check for a file tucked away somewhere. No findie, no workie. An implementation like that might even be passed off as a simple bug, if done cleverly enough.

Hey, you could even start a consulting business just writing code like that. "I want Amazon down, see? But make it look like an accident."

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I'm too sexy for my .sig.