UPDATE: A few years ago (sometime after the original posting of this article), Credit Card companies agreed to allow vendors charge fees for the use of their credit card. It is now legit for a business to charge for the use of a credit card.
UPDATE 2: It seems in 2023, there's a separate lawsuit against Visa and Mastercard by merchants who claim they are charged excessive fees due to antitrust violations. Although this is a separate issue from the one mentioned originally below in this article (back in 2007), it seems important to note it here. The settlement agreement (backup link) to end the 2023 lawsuit was apparently effective on August 1, 2023.
OUTDATED INFO: Have you ever run into a store with a sign posted that states they charge a fee for any purchases under a certain price if you pay with a credit card? Card Card companies have restrictions on when a fee can be charged. No fee is allowed for amounts greater than $1. If you come across a store that is charging a fee for any amount greater than $1, just leave and tell them why you are leaving. If you are a regular customer, perhaps gently remind them of this before you take off.
Then, report that place of business to your credit card companies. They will take it from there.
OUTDATED INFO: Have you ever run into a store with a sign posted that states they charge a fee for any purchases under a certain price if you pay with a credit card? Card Card companies have restrictions on when a fee can be charged. No fee is allowed for amounts greater than $1. If you come across a store that is charging a fee for any amount greater than $1, just leave and tell them why you are leaving. If you are a regular customer, perhaps gently remind them of this before you take off.
Then, report that place of business to your credit card companies. They will take it from there.