In Sony's favor, Sony excluded small claims. So for pretty much everyone this arbitration clause is meaningless. The limit for small claims is in the thousands of dollars (depending on state) [2]. The circumstances where Sony would be liable for more than a few thousand to a single consumer would have to be pretty extraordinary.
Also in Sony's favor, Sony did not choose to use the arbitration clause to set an onerous jurisdiction. Sony could have said all arbitration needed to take place in a specific city in the middle of nowhere. Sony didn't even pick the location of its headquarters; you can pick any jurisdiction. Most arbitration clauses I've seen set a jurisdiction that favors the contract writer, so I'd say this puts Sony in a decent light for not doing the same.
If you really wanted to find fault with Sony's particular arbitration clause, it would be that it is binding. Neither side can appeal the decision of the arbitration panel to a higher court. But keep in mind this cuts both ways, and it really isn't unusual. It is even endorsed in the United States.
I should also note that arbitration clauses can be voided if the panel can be proven to be biased. So this isn't necessarily a license for Sony to circumvent the law, at least against a well funded opponent. And anyone with the balls to sue Sony for any serious amount of money would be a well funded opponent.
[1] http://en.wikipedia.org/wiki/Arbitration_clause
[2] http://www.nolo.com/legal-encyclopedia/small-claims-suits-ho...
While the fraud committed from identity theft is generally in the several thousands of dollars, this is almost entirely absorbed by businesses. In the United States the consumer liability for credit card theft is federally capped at $50 [2]. Most credit card companies just go ahead and make it $0 to sound good in advertisements. As a side note, it is criminally foolish to ever use a debit card in place of a credit card because the liability limits are higher and more strict to enforce [3].
So yes, even for most victims of identity theft, small claims would more than cover their potential damages. Not to mention the legal fees to prepare the case would dwarf all but the most disastrous losses. Most people would be far better to take Sony to small claims court for the $150 filing fee and get the maximum $4000 or whatever and be done with it.
[1] http://www.bbbonline.org/idtheft/safetyquiz.asp
[2] http://en.wikipedia.org/wiki/Credit_card_fraud#Cardholder_li...
[3] http://www.ftc.gov/bcp/edu/pubs/consumer/credit/cre04.shtm
