They should get a ban if they broke a rule but the rule is beyond retarded. If they have the funds they should be able to spend it as they see fit. As long as they cannot leave a club in financial trouble if they want to spend 1 billion pounds on Messi they should be able to. All the current rules do is try to maintain the status quo and not allow anyone else to break in. Now though Liverpool fans have a massive interest in this all of a sudden and have become bitter and care about where the money comes from. Self interest, if you can kick them down you can maintain your top spot under the pretence of human rights.
If we care about actual fair play set a spending limit on all clubs equally for the season. Lets not kid ourselves this is about fair play.