Poloniex recently announced they will be taking action against unverified legacy accounts in a similar way to what Bittrex did.  The big difference being though that it's clearly outlined what will happen WAY ahead of time with plenty of notice for people to withdraw their coins if they wish.  And even after it takes effect people will still be able to remove their coins, just not trade them.

Unlike Bittrex which is a thieving piece of shit exchange that should have legal action taken against them soon.