WHO owns a bright idea? If the technology associated with an idea is new and the opportunities it offers are valuable, it will have many authors — most of whom may argue over ownership.

When disputes over the provenance of an idea become particularly turbid, disappointed entrepreneurs will look to the courts, which often are of little help. As Lawrence Lessig, a professor at Stanford Law School, said, “The general rule is that ideas are free unless strapped down by contract or patent.” In practice, a great idea is owned by whoever expresses that idea most successfully.

Consider the case of Mark Zuckerberg, founder and chief executive of Facebook, the fast-growing social networking Web site, who is being sued by Cameron and Tyler Winklevoss, twin brothers who were founders of ConnectU, another social network.

Today, Facebook enjoys much of the glamour that Google had when it was new. As of July, more than 30 million people, mostly young and college-educated, had registered on the site, according to the company. Facebook’s users share information about themselves with friends, send private messages to one another and hang out in groups formed around different interests and hobbies, where they can swap Web links and files like photographs and videos.