I can't see why this stable coins will be dangerous in the market, I mean all of the traders are only shifting their funds to this coins as a safe heaven during big dips but I don't see the traders staying long on these kinds of coins.
How are those coins safer than the $ or the euro?
Yeah, a bank can freeze your account and so can those that issue those coins, but no way the real $ will turn to zero in a few hours, unlike what can happen if the authorities raid bitfinex.
Stable coins are not a danger to the market, they are a danger to anyone dealing with them!!!