Someone got scammed and now YOU will have to pay the price!
Google will ban all cryptocurrency-related advertising.
https://www.cnbc.com/2018/03/13/google-bans-crypto-ads.htmlThat suits me really well. Got all my dogecoins nicked on cryptopia. 100 doges stolen on tradsatoshi (They have the best show treating customers like idiots!). Scammed again on bittrex and got my litecoins stolen on poloniex. So far no more trouble than expected on yobit (Someone is trading inside there i believe).
Those pieces of shit that runs the show today don't need any more understanding. Jail should fit.
Before you there is dozens of such threads opened and you should use search option before open new one.Google ban of cryptocurrency advertising is few day old news,and it will start in few months so there will be time to find alternatives.Also it is good in a some way that many scams and phishing sites will no longer be so easy to come up to the users.
Regarding all sites you mentioned,always be extra careful and choose those with most trust from the community.If you are lost coins on Bittrex and Poloniex than this is probably your fault,otherwise you can start thread in
ScamAccusations.
I can only say I've been for years in world of cryptocurrency,and nothing bad happened to me from any site that you mentioned.