SEATTLE — Presumably we could sit in our offices or our homes and stream away on the Olympics.

There is a hitch, though.

NBC owns the U.S. rights to the Vancouver Olympics, and, for this Olympics, it has clamped down on online live streaming of events.

Only hockey and curling will be shown live online, with all other events either shown live on television or held for tape-delay airing on prime time or late night television, says the industry publication Broadcasting & Cable in a story Monday.

The Web site for CTV, the Canadian network with rights to the Olympics in that country, is live-streaming events, but NBC has made sure that computers with U.S. IP addresses can’t log onto the CTV site.

(Quick explanation: IP stands for Internet Protocol, and whenever you communicate with your computer, it sends out an identification number that tells what country and city you live in. That’s why when you visit some Web sites, you get pop-up ads aimed directly at your location.)

It’s not unlikely some might try to find a way around not having a Canadian IP address.

That gets into some murky legal and copyright areas.

One way is to go to a site such as justin.tv, a San Francisco-based Web site that claims to be “”the largest online community for people to broadcast, watch and interact around live video.”” The site says what it does is not piracy, but simply individuals sharing video.

Through their Web browser and sometimes more complicated means, participants can put on the Internet a live broadcast of, say, an NFL game that’s not airing in your city.

Then visitors can join that particular “”channel”” and also watch the game.

Evan Solomon, justin.tv vice president for marketing, says the site has 30 million unique visitors a month, and more than 40,000 unique broadcasts each day.

Probably some members of the justin.tv community will broadcast live CTV Olympics coverage.

But be prepared to have that broadcast yanked abruptly.

Solomon says a particular live CTV broadcast on justin.tv will end if NBC happens to catch it and make a complaint to the Web site.

He says his Web site complies with the Digital Millennium Copyright Act and would “”expeditiously remove content”” that NBC complained about.

Justin.tv is accustomed to tangling with major-league sports and with networks. In December, according to the Kagan Media & Communications Report, ESPN and Major League Baseball complained to a House of Representatives panel about the growing threat of piracy on Web sites that stream sports broadcasts for free.

What about any liability for users of justin.tv?

“”Unfortunately, I do not know the answer to your question,”” says Solomon. “”I am not a lawyer, so I wouldn’t feel comfortable speculating on the legality of any user behavior.””

Professor Tom Anderson, of the University of Washington’s Department of Computer Science and Engineering, cautions those who are thinking about circumventing the NBC block on live Canadian Internet coverage of the Olympics:

“”Both sending and receipt of copyrighted material without permission is illegal in the U.S. In the U.S., the penalties for copyright infringement are draconian.

“”A more productive avenue might be for your readers to urge NBC to make live streaming of Olympic events available on the Web in the U.S.””