Buying medical marijuana on credit?

A little-noticed move by American Express to ban the purchase of medical marijuana with its credit cards has reignited a longstanding debate: How much can a credit card company control what you buy?

To the surprise of consumers, major credit card companies are making decisions about what they can and can't buy with their credit cards. What's off-limits? Legal purchases like gambling chips and donations to at least one controversial non-profit organization; in some cases, buying pornography is also restricted, and so, increasingly, is medical marijuana. Last month, shortly before Delaware became the 16th state to legalize medical marijuana, American Express told merchants that its cards could not be used to buy it.

Companies say they're protecting themselves against legal risk, but critics say this kind of corporate policy is an inconvenience for merchants, infringes on consumers' rights and amounts to moral policy-setting. "You ought to be able to use a credit card for any legal purchase," says John M. Simpson from the non-profit Consumer Watchdog. "It seems to me that credit card companies are imposing their moral values on the world." (from SmartMoney)