Ask HN: What would you do about identity theft?

My friend had his ssn/name pair stolen and used on several occasions. Mostly, other people are using the pair to buy subscriptions to television services or other mundane things; nothing worth hiring a private investigator or lawyer over but it worries him. What would you do if your identity was stolen?

I told him to change his name- simply one letter in his last name. If his new name is different, creditors attempting to seek false debts from his old name would reach a dead end. Unfortunately for him, I am not an expert.

Any ideas?