I have seen no verifiable data suggesting what you are stating. But as I said, if they are cooking the books, #Bitcoin will eventually reveal the foul play. You can't change #Bitcoin's code. We 100% agree, not your keys, not your coins.
It would be incredibly easy to find verifiable data to prove me wrong, but no one has seen that either!
Not to beat a dead horse here, but you are implying someone is breaking the law. All I'm suggesting is this: It does NOT matter. If they are toying with #Bitcoin they will be discovered eventually. ALL times you use a third party for something there is a certain amount of TRUST involved. Unfortunately that's the problem with laws and humans. Humans respond to situations REGARDLESS of the law to self preserve. Bitcoin fixes this problem of trust. Why people will eventually all be using Bitcoin and the Coinbases of the world will eventually move to Level 2 application where machines hard link to Bitcoin to eliminate the 3rd party trust problem. Or likely go out of business if they screw up as you suggest. So we are arguing over something that really does not matter. NEVER buy Bitcoin in an ETF. ALWAYS buy Bitcoin and move it to cold storage every few grand (or whatever you are comfortable with). Strike.me allows you to do that free.