I had a similar thing happen where my last name was also part of a trademark for a huge institution. As soon as I registered a domain with the name in it, I got an email from their legal department demanding I forfeit the domain to them or they would take legal action.

I replied that the domain was my surname, and that it wasn’t being used commercially at all, much less in the industry they’re in, and I actually got an email back saying they’d back off as long as I didn’t try to pull any funny business.