This has appeared in Guardian Unlimited:
Barcelona ends bar ban on badly dressed tourists
Wearing a T-shirt and baggy shorts to a chic cocktail bar is apparently a protected right in Barcelona. Two years ago, the Boadas bar put a sign at the door barring anyone in tourist attire. But the city office of civil rights recently overturned the ban, saying it was discriminatory. A decree says access to a public establishment cannot be denied for "reason of birth, race, sex, religion, opinion or any other condition or personal or social circumstance," which apparently includes taste. Other bars and businesses have rallied behind Boadas, defending its right to keep out what some call "low-quality" tourists.
According to Google News at the time of writing the Guardian is the only source of this information in any language on the Internet, though I have managed to find confirmation in Spanish that this case has been in progress. But I suppose that the Guardian has to concern itself with the interests of its holiday-making readers.