“This may be the last Christmas of online shopping without paying sales tax. A proposed online sales tax has been offered as an amendment to the National Defense Authorization Act, much to the ire of opponents. The Marketplace Fairness Act, and its House counterpart the Marketplace Equity Act, seek to clarify, and arguably overturn, a 1992 Supreme Court ruling that requires retailers to have a physical presence in a state in order to collect sales tax on goods.”
http://dailycaller.com/2012/12/04/online-sales-tax-to-be-added-to-defense-authorization-bill/