Before i don't think bittrex one of the scammer. But after last event "Disabled User's Accounts"
Last month without any single notification. Im agree that bittrex is a very dangerous online exchange. More than 1000 accounts unable to withdraw their funds. All lost thousands of dollars inside bittrex and no body able to get one cent. Most accounts form countries that hard to get a full enhanced accounts. Even with Enhanced and approved accounts users unable to withdraw because Bittrex US-based business and US dislike some countries. ...so bittrex now face some trouble with OFAC match and those accounts almost registered 2~4 years ago and that not allowed ofcourse.
Now Bittrex try to erase all old data and seem like clean exchange that follow the US rules.
You can check this event at twitter and official bitcointalk forum. How bittrex killing Hundreds of trader's dream by catching them and disabled their accounts.
I think now bittrex is scam and want to keep user's funds forever. .