A personal trademark has only limited protections if it is not registered. It is also not clear that he wanted trademark protections to apply, since he did not

A personal trademark has only limited protections if it is not registered. It is also not clear that he wanted trademark protections to apply, since he did not seem to use the (TM) symbol that is allowed prior to registration. He could challenge an attempt at a trademark application, but the other FutureStack might have a good case given how many people confused his account for the conference.