Well, first of all, there aren't millions

It is set to display the quantity in mBTC.

That is, there you get 331831.98344229 BTC. Secondly, I checked the very first address, it is the address with bitcoins stolen from MtGox in 2011.
1FeexV6bAHb8ybZjqQMjJrcCrHGW9sb6uF
I am an infamous Bitcoin address containing 79,956 BTC stolen from MtGox in 2011, coins which have never moved since. Many claim me but no one has my key.
I assume that the whole wallet contains the same stolen bitcoins.
And yes, this wallet has not been hacked so far, so I doubt you can do anything with them.