We succeeded in auditing Poloniex's cold storage account!
Poloniex has sent 30m BTS from their cold storage account to their hot wallet, so they've not lost access to these funds.
Poloniex had failed to move any cold storage funds into their hot wallet for 10+ months despite running out of hot wallet funds multiple times. It was rumoured that they had lost access to their cold storage funds, if this was the case then they were/are running a fractional reserve.
In response to raised concerns, Poloniex prove proof of cold storage fund ownership by moving 30m BTS from the coldstorage account to their poloniex hot wallet (http://cryptofresh.com/tx/40b2b20e32eb4592e08d50d35bebce668ee0caf1).
Great work, less than one day Poloniex support turnaround - not bad! ;D
Poloniex has sent a second 30m batch from their cold storage to hot wallet: http://cryptofresh.com/tx/78f75430f14e773658b6b736b3fb2114a89069d7
This is great, rather than waiting on tickets for weeks we can just spam their cold/hot wallets with pololostkeys containing memos requesting they top the hot wallet up! :)
It is worth noting though, that they did not return any of the pololostkeys tokens nor did they accept the proposed transactions, that said the main purpose was for them to prove ownership of the BTS & they did!