Congress is considering legislation that would require closed captioning for video streamed on the Internet. Some programs and networks caption these Internet streams, but others do not. The 21st Century Communications and Video Accessibility Act of 2008 would apply the same standards imposed on television broadcasts. Congressman Ed Markey held hearings this month but has not introduced a bill. The biggest problem is the lack of a single technology that delivers Internet video. Viewers use different programming formats to receive the stream.