I think the important thing is that nobody should be allowed to be a Nets fan just because they happen to live in Brooklyn. Fandom takes time to develop. Sure, go to the games, but if you weren’t a New Jersey Nets fan, don’t start calling yourself a fan this year. It just invites criticism.
Here’s a parallel, 10-15 years ago if someone said they were a fan of some MLS team, you looked at them like they were crazy. Not just because soccer ain’t Amurckan, but because unless you’re under 12 it’s kind of weird to be a fan of something you haven’t had the time to develop any real allegiance to. Similarly, if your buddy had an arranged marriage, you’d be fine with him saying, “You know what? She’s good looking and seems kinda cool, I’m gonna run with this.” But if he said, “I love her and will support her forever,” you’d think he was crazy.
Brooklynites, go to Nets games. Enjoy the games. Cheer for the team that represents your city. But please, unless you liked them when they were in the Garden State, don’t call yourselves fans yet.