This is way too dramatic and unprofessional for my tastes (Facebook chat logs? followed up by a generalization about the 8.3 million strong population of NY based on experiences with one guy? a little growing up is in order.)

I'm sure this can be debated and I could be wrong, but I don't feel that ideas are worth fighting over. If code is stolen, that's not cool. You can build two codebases based on the same idea and they will be valuable in different ways. If someone takes the time to follow through on implementing "your idea", they still most likely worked hard to get it done and deserve credit for that.

The best way to deal with this is to compete. Write a better app. Ideas are cheap.

Ideas are cheap - good ideas aren't. Thanks for the redaction observations - I edited the article.

Most ideas aren't "good"--only ideas with strong implementation are "good". Nobody gives a shit about your hackathon project that you can't manage to make a business out of.

If you really think this is worth is, go build a company and show him wrong.

You wrote: "Microsoft owns the idea if they want to. By participating in the competition we (and I) agreed that Microsoft can claim rights over the idea and use it as they want."

I think you are wrong about it and Microsoft doesn't own those ideas. Can you link to terms or rules where it says what you claim?

Carry on, nothing to look at. Most of US'es big tech poster children have done / will do this.

"Good Artists Copy; Great Artists Steal"

"Who said that?"

"Eh, some artist."

So you gave the idea to Microsoft, then abandoned it and now you are angry someone from your team picked it up again and offered you shares?

We did not abandon the idea, we took a break.