Their policies are predatory at the very least. When there is a high network txn load it is highly likely that even txn's with fees will be delayed. Perhaps this is their way of deterring sophisticated double spend attacks, but it hurts the average user way more.

They are thieves no different from the rest of the ponzi scammers out there; and mark my words, don't be surprised when they disappear with everyone's bitcoins one day (or they get "hacked").