Hidden is not the same as gone. They are being masked. It is a very easy thing to do. Part of the code is actually in a Q drop. So the data still exists you just can't see it. It would take way too much processing power and time for them, even with help, to go through and erase that much data. It's too chancy that someone would make a mistake and delete the wrong stuff. Also if for some reason they were sued, which they should be, they would want a fall back. That is just smart business.