Maybe it's a bug, a design oversight, or prevented by some really odd technical issue, but for whatever reason, I can't currently open threads on my activity feed as new tabs or windows. For me, this makes it incredibly impractical to view more than a single thread when visiting my activity feed. I would love to use it, but I'm not going to bother if I have to reopen it, go to the desired section, and scroll back down every time I want to look at something.