Voting for someone because he looks suspicious is not a good reason. Especially because he hasn't posted anything yet.

Anyway, there's the possibility of him being an alt, but we can't be sure if he is or not. Also if you want to lynch someone because he "might" be an alt, you've potentially bummed over a new forum member. Is that really the signal you want to send from the forum? Once you actually have an in-game reason to lynch him, by all means, but until then.
Also if it is anyone's alt: The jig is up. You've had your fun. Now let's play the game.