A YouTube video of dancing toddlers sparked a lawsuit that could establish an important legal principle for user-generated content online. Universal Music Publishing had forced YouTube to remove the half-minute video by Stephanie Lenz, which featured her two children cavorting to a Prince song (Prince's songs are published by Universal). Backed by the Electronic Frontier Foundation, Lenz sued the music company, arguing that the video was a fair use of Prince's song and that Universal had acted in bad faith. The editorial board took up the case last month, throwing its support behind Lenz and the EFF. On Wednesday, a federal judge agreed (kinda sorta), ruling that copyright owners must consider whether a suspected infringement is a fair use before demanding that it be removed from the Net. The ruling could put a crimp into copyright holders' increasingly automated efforts to fight piracy online. Read more about the decision on the Times' Technology blog.