The bank says the card holders were victims of what's called "a point of sale compromise." That means thieves acquired card numbers at a store or ATM -- not by hacking into a computer system. Customers aren't happy.
"I have to go back through all the different places that I have charge accounts with and give them the new number and it is just going to be a problem and it is something they should have had better security on," said Alameda resident Marty Taylor.
Wells Fargo believes the "compromises" took place somewhere in Berkeley, they're not sure where yet. It's important to note, that Wells Fargo customers may not be the only ones affected, other credit or ATM cards may have been compromised.
You can contact your card company to make sure.