I see this on a smaller scale where ICs leave a company and take a copy of "their" code (ask Sergey Aleynikov [1] if that's a good idea). It's not yours. If you ever use it you could face legal consequences. And there's no code I've ever written that I wasn't convinced I could write better from scratch the next time if it ever came up. Side note: it never has.
Don't be that guy who takes the check and then expects control. Don't be that guy who is convinced the new owners are messing it up and then goes out and does the exact same thing..
Move on.