I've noticed during the contest that we can see all the hacks in our room.
Now MikeMirzayanov says that it was a bug and will be fixed soon.
I think it really will be bad if there are tons of hacks. But it is very useful to know which problems can be hacked (I mean which problems was already hacked by someone). Can you add number of successfull and unsuccessfull hacks on each problem to the PROBLEMS page?