You can't trust anyone these days. I used to work at a small startup and one of my friend who worked in another startup, just used their code base, modified the design, changed couple of functionalities and started his own portal. Not only that, whenever founders ask for live date, he will say couple of more months, but eventually he quit and started his company. Since the product is very mature than the original, he somehow got acquired by some big guys for handsome amount. I guess, this puts the founder under the rug and I've never seen him again! These are the kind of situation, which make startup founders afraid of their IP, and stuffs.