You're mistaken about activity. If they delete their post they lose that activity so this wouldn't work. The only time you won't lose your rank is if you're a ledgendary (and possibly Hero). Farmers are probably just regurgitating things others have said before so that's why they might look similar.
Farmers might not know that either. I
found the post which I thought was a duplicate of another post made a few hours (maybe, a day) before by someone else. I felt that I read about that "some Chinese expert" somewhere on the forum (in the original post it was "10,000", though). But I didn't find anything similar on Google (relatively new posts are not cached by Google immediately), and I decided that the original post was deleted...
This is the post I refer to (emphasis added):
New crisis will be early or later. But nobody can say exactly when. And that is the most scare.
And I also heard recently the prediction of some Chinese expert that bitcoin will reach 10 000 $ soon and that will be not the last the highest jump to bitcoin. What is going to be next? Maybe you are right abut banning bitcoin.
If I'm right after all, someone will get caught eventually
I figured it out, they have say 100 accounts enrolled in yobit and they post the same message to each account and wait for you yobit to credit it, and then they delete it and post it on another account