Further to the banning of 3G hotspots at the London 2012 Olympic games, to protect the communication of referee and measuring devices used within the different sports at the London 2012 games, from wireless interference during large public events.
The Olympic’s have “Wifi Police” patrolling the Olympic venues who are equipped with frequency trackers looking for unauthorised 3G hotspot offenders or wireless access points using the restricted Olympic frequencies.
“Personal/private wireless access points and 3G hubs (smart devices such as Android phones, iPhone and tablets are permitted inside venues, but must not be used as wireless access points to connect multiple devices).”
For more information jump over to the Reddit website where the story originated, which has more details on the specifics the WiFi Police at the London Olympics are looking for.