Sarah Deutsch is steaming. The attorney for Verizon Communications regularly scours the Web from her Arlington (Va.) office and finds hundreds of new sites that use variations of Verizon's name. A mid-December browse uncovers a constellation of Verizon-inspired domains such as verizonpicture.com, vorizonringtone.com, and varizoncellularphone.com.

What angers Deutsch is that none of the sites have anything to do with Verizon. Instead, they're registered by companies like Nassau (Bahamas)-based Wan-Fu China and Pompano Beach (Fla.)-based Moniker.com. They're engaged in a little-known activity called "domain tasting," a legal practice that lets registrars snatch up Internet domains for five days at no cost. Typically, these companies jam the borrowed Web sites full of ads and pull in money as visitors click on the ads. Because they can use the Web sites for no charge, these firms are registering mass quantities of domain names each day, getting under the skin of companies trying to protect their brands online. "Domain tasting is destabilizing the entire domain name system," says Deutsch. "People are purposefully exploiting trademarks and misleading consumers."

The practice has soared in the past two years. In late 2004, roughly 100,000 domain names were tested on any given day, and now, the number has ballooned to 4 million, according to Jay Westerdal, chief executive officer of the domain consultancy firm Name Intelligence. Experts estimate that less than 2% of the sites that are tried out for a few days are ultimately purchased by registrants. It's a bit like being able to get clothes from a store, wear them for five days, and then return them at no charge.

With an ever-expanding menu of domains on offer, tasting will likely continue its exponential growth. There are more than 250 suffixes besides ".com" to choose from, and more companies are getting in the game of domain registration. Today search engine giant Google announced it will work with top registrants GoDaddy.com and eNom to register addresses ending in ".com," ".net," ".biz" and ".info."