I know but I actually do not have any headache unless the event is in the recent time. May be late 2018 to current time.
That sounds about right. I started tagging account sellers/buyers at some point in 2016, and I'm sure I've missed many of them. That's just the way it is. There are only so many hours in the day I was willing to spend handing out red trust, but there are/were just so many of them.
At this point I personally would not go back to 2017 in order to tag an account dealer unless the member in question is extremely problematic or there are some other circumstances happening that would lead me to believe that the person needs to be negged. I've not yet run across that.
But I don't know--it seems like the market for bitcointalk accounts has waned somewhat in 2019. Am I wrong about that?