I was able to get a custom taxonomy associated with topics only partially working with bbPress 2.6a and WP 3.8, but the performance of queries was terrible compared to using postmeta. A query using a custom taxonomy that took 3.8 seconds took only 0.01 seconds with the same information stored in postmeta. So performance needs to be taken into account.
Thanks very much for posting your solution, Roger. I had the exact same frustration. And no, I found no better way to do this. I had tried using $post->post_type but that gave unexpected results.
There is no twitterfeed on my forum and I have the problem.
I am having the same problem. It is the same spammer or technique as newform and just started a few hours ago.
