The International Olympic Committee has filed a lawsuit in California accusing at least six websites of selling illegitimate or nonexistent tickets.
Reuters has reported that the ticket scam is international with victims in multiple countries. While the IOC is taking action, it appears unlikely that replacement seats will become available. Tickets for events in the host city of Beijing completely sold out last week.
One of the websites in question was named in the article — www.beijingticketing.com — was said to be up and running, but is now down, or moved.
The Organizing Committee has official information regarding legit tickets here.