AFAIK you can only claim a trademark-violation if someone is (for example) selling stuff (so you couldn’t sell stuffed animals that look like an early Mickey for example).
A webserver listens on port 80 or 443. Neither port can be claimed by a normal user (no port below 1024 can). But yes if you manage more than your own user on a desktop AND these other users are not allowed to start programs on their own THEN a firewall can be helpful; but this is not a normal situation for a desktop-client, isn’t it?