I cannot see this ending well for alternates. HitBTC and Poloniex are so deep into Monero, where unless they start covering their ass now, then we're looking at international raids and confiscation of coins like the Silkroad. It will be a very red week and many alternates would see 5%-10% of their total supply confiscated as evidence (and presumably later sold at some auction). There is a remote possibility, much like Bitcoin right after Silkroad, that the liquidity being seized could result in skyrocketing prices.
Actually Polo and others have the same "problem" as any exchange which converts USD or EUR to local currency: none, no problem at all.
They don't know where your money came from, but they ask for your ID. Polo does the same. Both follow the rules.
I don't think that the authorities will confiscate anything, at least not from Polo. But the price may rise because the rules may get enforced better or made more strict and the ones that want to buy anon coins for illegal stuff may buy more "just in case".