Why are there no messages at all? I clearly remember that there were some?

Probably the moderator has deleted them :(

ALL the messages? Of course where could be couple of source messages, but why all the ideas were deleted?

I guess he wants not to cheat, e.g. submit sources or to make us think of the problem ourselves :), anyway I think that it's good to leave at least the ideas, but it's probably quite a task, and on the other hand, during competitions we can't use hints :)