Just looked down my "threads I am on" list and there are several where the last post was 2011 or 2012, not been responded to since. I almost replied to one saying "Oh I remember a similar thread...." and realised before I posted that it was actually the thread I was replying to!
These were in the list before threads that have had activity in the last 48 hours.
Anyone else had this? Is it because they are being read by bots/journalists/whoever so that is making them seem active?