When a video clip goes "viral," spreading across the Web at lightning speed, it can help rocket its creators to stardom. Alas, the clip can also generate work for corporate lawyers.

As anyone with an Internet connection and a love of cupcakes can tell you, "Lazy Sunday" is a tongue-in-cheek rap video starring Chris Parnell and Andy Samberg of "Saturday Night Live." NBC first broadcast the video, a two-and-a-half-minute paean to New York's Magnolia Bakery, Google Maps and C. S. Lewis, on Dec. 17.

Fans immediately began putting copies of the video online. On one free video-sharing site, YouTube (www.youtube.com), it was watched five million times in a few days. NBC soon made the video available as a free download from the Apple iTunes Music Store.

Julie Supan, senior director of marketing for YouTube, said she contacted NBC Universal about working out a deal to feature NBC clips, including "Lazy Sunday," on the site. NBC Universal responded early this month with a notice asking YouTube to remove about 500 clips of NBC material from its site or face legal action under the Digital Millennium Copyright Act. YouTube complied last week. "Lazy Sunday" is still available for free viewing on NBC's Web site, and costs $1.99 on iTunes.