Hearthpwn

I just played a druid by the name "heaken" of and he started off the game with 3 Alarm-o-bots which I killed and then another one 2 turns later. Later in the game he also used 3 starfalls too. This was in casual and not arena so I don't see how he could have more than 2 of each in his deck. IS this a new hack or something?

You're probably just wrong. With the way Hearthstone is stored and the interactions with server, it can't be hacked the same way as other games.

99% chance that you miscounted. Or forgot that Alarm-o-Bot returns to his hand when it triggers.

I recommend turning on logging (see http://www.reddit.com/r/hearthstone/comments/268fkk/simple_hearthstone_logging_see_your_complete_play for instructions) and if something dubious happens, open a support ticket with Blizzard and send them the debug log.