It's a joke that would be funny only to a sixth-grader. But a top Democratic senator has real concerns over the possibility that website addresses ending in ".sucks" may be used to mock people or organizations.

Senate Commerce Committee Chairman Jay Rockefeller said Wednesday that a Web domain like .sucks has "little or no socially redeeming value" and could be used for extortion.

"I view it as little more than a predatory shakedown scheme," Rockefeller wrote in a letter to the Internet Corporation for Assigned Names and Numbers, the independent group that manages the Web's address system. "The business model behind this [domain name] seems to be the following: force large corporations, small businesses, nonprofits, and even individuals, to pay ongoing fees to prevent seeing the phrase 'sucks' appended to their names on the Internet."

ICANN is currently implementing a plan to expand Web endings, known as generic top-level domains, well beyond the traditional .com and .org. Websites could soon end in words like .car, .music, .love, .pizza, or thousands of other possibilities, including brand names such as .coke.