Why am I getting alerts for new threads?

Twice I've gotten alerts for new threads:

Goldstein the Space Jew started a thread called Yet another mindless shooting in America..... There may be more posts after this.

Teh Baba Returns started a thread called Imagine Dayton's reaction to his wife telling him she's having an affair with El Chup.. There may be more posts after this.

Is this something new?

Go to alert preferences and change it. You can do that by clicking your name in the top right corner.

Also, have you subscribed to any threads?

Already looked into it.

I don't see any option to remove for when someone starts a thread that I'm not involved in.

Nope.

In fact it's only your thread and Baba's thread that popped up like that AND I didn't know about either thread until I saw it in the alert box.

I'll refresh the board data, and see if that clears this kind of issue.

Just had a third one:

We Are Borg started a thread called This is America's moment of truth: Stop Donald Trump. There may be more posts after this.

Thanks. Looks like I was watching it. I just stopped watching it. We'll see if that works.