IANAL, but: If they're operating, they have a common-law trademark even if not a formally-registered one. A same-named service of the same general functionalit

IANAL, but: If they're operating, they have a common-law trademark even if not a formally-registered one. A same-named service of the same general functionality would certainly cause consumer confusion, and possibly damage to their business, putting you at risk of a legitimate lawsuit. Legally and morally, they won the race to that name, so for trade purposes in that field of business, it's theirs. If you love the idea, there's surely another good name. Perhaps after studying them, and noticing another area of differentiation, that can inspire another name. You might be able to sell them your holdings, but don't expect much and the offer would have to be delivered very delicately so you don't seem like you're ransoming off properties they already have a strong claim to (and that in their mind, you might have acquired just to shake them down).