Question for moderators

Over the last few days i have noticed a big increase in threads being added to , say 2 hours ago , but when you look their is nothing new on them and some posts are a couple of years old.
Example ... their is a "steam account " thread that is 2 years old but nothing new on it.

I also get notifications of somebody adding to a thread that i have started but when i look their is nothing new on them.