I'm using poloniex for trade as well as form lend a small amount. And i never had any problem with lending and as above mentioned, poloniex taking collateral from their users so even if the your loan taker has scammed you can still get your money back.
To be honest, you as lender have no collateral if control over collateral have someone else - here Poloniex.
Is this safe? Ask Karpeles..
