Washington DC - taxation without representation

One of the first things that people who visit the U.S. Capital, Washington DC, will notice is the message on vehicle license plates (number plates) stating "Taxation without representation".  These protest plates have been in circulation since November 2000 and note the fact that while the nearly 600,000 residents of DC get a say in the Federal presidential election, they have no vote in the U.S. House or the U.S. Senate.