A sticker was recently spotted in the window of a taxi cab in Dallas, Texas, stating that a person’s identity may be stolen if they use their credit card to pay cab for their ride.

“WARNING,” the sticker read.

The method used to authenticate credit card transactions for approval is not secure and personal information is subject to being intercepted by unauthorized personnel.

Is this warning as bad as it sounds? It is not easy to answer that question so says Ondrej Krehel, the information security officer at Identity Theft 911. Although usually the real answer might be the simplest, Krehel says: A large number of taxi drivers would prefer their passengers to stick with paying by cash. Krehel says,

My first thought is whether this is just the driver trying to get people to use cash.

There is a detailed history of taxi drivers contesting interchange fees associated to credit cards, which are taken from their profits. Although, it is difficult to understand if the sticker is just a maneuver without more information relating to the credit card terminal situated inside the taxi cab.

The regulations regarding security of these terminals have been written by the Payment Card Industry Security Standards Council, which are a group governed by, American Express, Visa, MasterCard and some other major credit card companies.

They develop the data security parameters that control all kinds of credit card readers and networks. This could mean that the taxi company makes use of older terminals that are not covered by the latest industry standards, Krehel states. Or it could be that the terminals are indeed new but were not installed correctly, either way it looks as though the sensitive information is not being encrypted properly.

The PCI Security Standards Council has failed to respond to emails and telephone calls asking for comments on this situation. But you have to ask why any business would advertise the problems it is having with trusting a credit card network.

No matter what the answer is, travelers using in that particular taxi may not wish to use their debit card to pay cab for their journey, in case it allows someone to gain access to their checking account, as these accounts can provide less protection than credit cards.

Certainly that could be a reason to use a credit card rather than a debit card,

says Gerri Detweiler, Credit debt expert.

But still, that doesn’t make you feel very safe, does it?