NDA Breach In Question

[hrm]

Hello there, I'm an entrepreneur who sits on the board of advisors for a few companies. One of the companies I was working with, which is in its very early stages of development, has changed their idea and started to implement the exact same ideas that my company is doing.

That however, is not kosher with me, and they've basically turned into a direct competitor to my company, without my consent, and using ideas that I gave them insight into ( which this is all documented ). When asking the person if they thought it was wrong and that they know the information they replied "I considered it, but I did it anyways."

Also, it might be wise to add I have documentation of many of our conversatinos about how our system works, conversations and agreements with this person, etc.

The only NDA/Non-Compete we've ever had was verbal, however it's documented that I am on the Board of Advisors of the company, officially. However, the fact that he admitted to knowing it might have been bad is pretty good evidence in itself, no?

Well if anyone could let me know that would be great. Thanks.