Earlier quoted context omitted.
Trademarks in the US don't need to be registered to be protected, like copyright (but unlike patents). If you have established use of a mark before the registration (or use) of a competing/conflicting mark, you can defend it. In fact, registration arguably provides no protection other than the fact that it makes it easier to search for your mark in the USPTO registry.
> In fact, registration arguably provides no protection other than the fact that it makes it easier to search for your mark in the USPTO registry. Isn't the trademark legally yours if you register and no one challenges for some period of time (I want to say 7 years)?
Massive corporate behemoths have lost local TM use because some mom-and-pop store was using a trademark first.