1. A coin listed on Polo skyrockets.
2. Polo disables coin withdrawals for that coin, under the guise of "wallet maintenance issues." (though deposits continue to work just fine
![Sad](https://bitcointalk.org/Smileys/default/sad.gif)
3. Polo sells your coins on a different exchange.
4. The coin plummets back down to earth.
5. Voila! Suddenly Polo's wallet maintenance issues for the coin are conveniently resolved.
6. Polo buys back your coins at a cheap price and reimburses them to your account, pocketing the difference.
Polo is basically short-selling your coins whenever one of their wallets goes offline.
I've watched this happen too many times over the last 4 years to believe anything else.
Perhaps now that they are a part of Circlejerk they will behave more ethically, but I doubt it.