Thieves seem to take pride in keeping up with the latest technology. These days, it is less common for a potential thief to simply steal your wallet, which could lead to a confrontation. It is more common for thieves to commit credit card fraud by stealing your credit card details.
Unfortunately, there are scanning devices that can access the details from your RFID credit cards while they are still in your wallet. This is a discreet way to steal from you, so you should take care to ensure that your cards remain safe.