What are the liability risks of shared startup ideas?

I've been working on a startup plan, and, per the advice I've seen many times, haven't kept it a secret, but rather have talked to a lot of people about it, and gotten some good ideas and direction. I'm not worried about other people stealing my ideas per se--execution is always the trick, and I've got an above average skill set in that regard.

What I'm worried about now, though, is whether those conversations have opened me up to liability later in terms of those people whose ideas I have incorporated coming back and claiming that they are entitled to some stake in the resulting company. To be clear, there's no sharing of code or other artifacts involved--just discussion of ideas.

So the question is, can people make a claim against my product if it incorporates ideas they originated? If so, is there a way to protect myself in that case?

Secondarily, if I discussed the possibility of collaborating with another entrepreneur but later executed on my own (with no products produced collaboratively), does that change the answer above?

If it matters, I'm in the US, so that's the relevant legal context.

Well I think it would come down to a burden of proof in court (not a lawyer etc).

If it was just a conversation over drinks I don't think they have much call. If they spent weeks writing up ideas then maybe a little bit.

If you grow to as big as facebook then they may try it on ... but people will anyway. If you make a nice sized company they probably wouldn't bother.

Risk wise I think it is pretty low, but its really a question for you: Are there any personalities in the people you have talked to that are likely to make the claim?