http://en.wikipedia.org/wiki/Steve_Jackson_Games,_Inc._v._United_States_Secret_Service

Legality really doesn't seem to be a huge factor in whether the Secret Service can inconvenience you. And if they raided a gaming company, I could see them plausibly raiding an AI development organization.

That said, I don't see anything to suggest it's particularly likely, but a government investigation, all by itself, is incredibly disruptive even if you don't end up guilty of any crimes.

Edit: Fixed from FBI to Secret Service.