i was trading on bittrex for a few years
then early november my acount was disabled without warning all locked out cant take my coins out nor trade.
they disabled my acount before posting the notice about legacy acounts. all i got from suport was 2 msg about getting verified and some crap then all i got was your account is under review bla bla even when i sent an other ticket from a unrelated issue seems support is locked out aswell internaly. so they are a scam for some people you could be next. here is proof of the shady pratices i found.

 as you can see in web archives here dated 18 octobre 2017 its a notice from bittrex from 2016 https://archive.fo/19xjq you can clearly see it states . Please check below to see what limit your account falls under.

Unverified Accounts created before 08/01/17: 0.025 BTC (or equivalent) per day.

so legacy accounts had no reason to think they would be locked out of funds . here is the updated notice from 30 nov 2017 after most people having problems accounts were locked out https://archive.fo/VXjZm here is states lease check below to see what limit your account falls under.

New/Unverified Accounts: Unverified accounts have a 0 BTC withdrawal limit.

as you can see they again updated an old msg from 2016 like if they posted this over a year ago . me like many others did not think an old over 1 year old notice was worth reading because we expected to allready have done so , bittrex clearly is doing something shady by editing an old msg multiple times to suit thers current needs.