The Senate Committee on Commerce, Science and Transportation will hold a hearing on Thursday about the Internet Corporation for Assigned Names and Numbers' controversial plan to allow companies to purchase brand names and other words as top-level domains.

A top-level domain is the string of letters to the right of the last dot in the URL. ICANN intends to accept applications between Jan. 12 and April 12 of next year.

Dan Jaffe, executive vice president of the Association of National Advertisers, is slated to testify against ICANN's plan. The ANA argues that companies would have to pay hefty fees for “defensive” registration -- that is, registrations of their own names -- in order to prevent them from getting scooped up by others. Registering a new top-level domain costs at least $185,000 and operating it costs $25,000 a year.