I've found a willing lawyer if there are people interested, but the status of the case will depend of the number of victims...
have you managed to track down other victims? at 1800 BTC generalized loss (1620 BTC if 10% was refunded) there must be some big lenders affected. i'm surprised at how quiet this story has been.
i'm assuming polo hasn't said a word since they refunded the 10%? they should at least establish some sort of payment plan out of their profits like bitfinex did after they were hacked.
I've found only 3 other people so far! Don't know where to find the other victims... And no news from Poloniex since they gave 10% back. I've asked support about waht's next, but no answer so far...
Now getting legal advice, I've been told that proving there was a fraud would be very difficult, unless having access to Poloniex's whole data, but there was definitely a mistake. Things like this, that CLAM crash because of crazy margin trading, should never happen.