I don'n ever have any issue with poloniex yet. so, what is the issue of you?
So your sample size of ONE makes you think that no-one else is having issues and everyone is on a fud campaign?
I personally don't use poloniex but I think it's a pretty big and fine exchange that many people use right? I realise this post is very old but is/can it really be a 'scam' exchange?
Scammy behavior on selective accounts it looks like, I personally think they think they can rip off unverified accounts because most of those don't want to KYC which they are making mandatory. If they get the coins from even half of those accounts they are seeing a great payday.
The world of bitcoin stock exchanges is a wild west, and Poloniex is also struggling with negative reviews. However, there are many regular users and supporters who trust the stock market. You will not lose money with Poloniex, but you need to read them properly to keep you from surprise.
I had no problem yet, and all the transactions went as they had to. For low fees, Poloniex is still a used currency exchange for me.
There is no doubt in my mind they are manipulating the margin order book.