I would be surprised if that is a poloniex address. I think they move most of their coins to cold storage shortly after receiving them, and no coin have ever moved from that address.
My poloniex address looks similar & a similar balance.
I've never seen a cold storage sweep, like what you used to do.
I was thinking that since no coins had moved out of the address it likely wasn't an exchange address, but I see now one of the deposits has moved. I guess I was wrong.