British newspaper The Guardian recently ran a report detailing the extreme lengths the International Olympic Committee (IOC) forces governments to go to in order to protect the interests of sponsors. Shortly after London beat New York, Moscow, and Paris for the chance to host the games the British government passed a particularly draconian piece of legislation known as the London Olympic Games and Paralympic Games Act. The law stops companies from aligning themselves with the games if they're not official sponsors, in a similar fashion to advertising restrictions around the Super Bowl.
Where the policy differs, however, is in the scope of the protection it offers sponsors, which goes much further than the obvious examples of words and phrases like "Olympics" or "London 2012." Any advertisement with two offending expressions from a list including "games," "two thousand and twelve," 2012," "twenty-twelve," "London," "medals," "summer," "gold," silver," and, of course, "bronze" would likely be outlawed. Locog, which is in charge of organizing the London Olympics, threatened legal action against an event called the "Great Exhibition 2012" due to its use of "2012," although it later withdrew the complaint.
The law also affects smaller businesses, as well as those of you that are traveling to see the games. Pubs will be prohibited from displaying signs inviting people to "watch the Olympics here," or even to "see the London games here." If Locog follows its guidelines strictly then the IOC could press for criminal charges against visitors posting images of the games to Facebook or Twitter, although it's more likely that the rules are in place to prevent companies from exploiting the images commercially.
You can get a full run-down on the branding protections in place at the
Olympics summer sporting event at the source link below.