RFID tags

Radio Frequency Identificatio (RFID) tags have been under development for years. They promise an effortless way of keeping track of inventory by sending a radio frequency to an object which has the RFID tag attached to it. The RFID tag then sends back a signal in regards to information about itself. Are there any inherent dangers in using such a technology?

Here is an article in Slashdot about Walmart and there "insistence" on their vendors using this new and soon to be "ubiquitous" technology: slashdot.org...