Pretty much what Lauda said, I remember awhile back there was an absolute wave of spammers trying to target old posts to bump and make it look like they were just contributing to the discussion but they were giving such generic responses it was easy to tell them apart. If they're just generic "Yes, I agree" posts and so on you can just report them, they add nothing to the discussion I think that some people even try to make more convincing posts too but they abuse it too much and you get several topics from a few months back being bumped up and it's really obvious what they're doing so I just report them after that.
You don't need to worry about getting people like this banned, they're just obnoxious spammers trying to fake being real members. I think there are also certain users who are trying to make generic topics about what sort of food people like and so on in off topic but really with that kind of thing you can only wait and see how far they push their luck.
It really depends on the situation. If they bring up a old one but make a relevant and really constructive post the it is okay. However, if they dig it up without a good reason it is likely going to be deleted.
I see. Thanks! I know a forum where these kinds of people gets warning for such action so I was wondering if this is tolerated in here. I just don't like seeing those kind of people, doesn't even make sense.
Anyway, I'll be locking the thread now. I finally got the answer to my question so yea.
regards!