You can freeze your credit with all 7 credit rating agencies (Experian, Equifax, Trans Union, and the 4 smaller ones whose names I always forgot) although that may not have protected this case because it is alleged Cash App does not pull your credit before opening an account.

Also opening a Cash App account yourself (even if you don't use it) is weak protection because they allow multiple accounts.

So if there as a defense I don't know what it is. Hope that identity fraud done with your info doesn't happen in a state with aggressive yet lazy/careless law enforcement.