I'll let temery answer definitively, but I don't think so. If you posted in any of the threads, however, and don't want the alerts, just go to the first post on the page and on the upper right, click "Unwatch Thread".
Whew - that was a lot of typing without really answering your question.
I've been asked this somewhere else, but I'm not sure it was here.
I'd like to see something similar to what reddit has - the "hide" feature. My guess is it'll be in a future update. If not, I'll look into doing it on my end.
After looking into this, I think it can be done in the next week or so. There is an available add on. I just want to see how stable it is before installing.