BT Wi-Fi is the exclusive hot-spot provider for the London 2012 Olympics, and a promise made in 2011 to have some 500,000 Wi-Fi hotspots across the capital has been met. The celebration for meeting this target was to deploy new wi-fi hotspots along 27 miles of the River Thames.
The hotspots are a mixture of commercial deployments, and BT Total/Infinity customers offering access via the partner Fon. Though while the number of Fon sites is increasing, oddly in the TV advertising for BT Infinity it is neglected for the risky prospect of sharing a private Wi-Fi key with pretty people you don't know very well.
The Olympic Park Wi-Fi deployment is apparently the largest high density Wi-Fi installation ever, and the density is the big reason why personal Wi-Fi hotspots are not allowed. How the Park controls this was apparently spotted by a twitter user, with we presume once a MiFi that has been left on is found the owner is politely asked to turn it off. The Olympic Park having someone checking for rogue hotspots, seems over the top, but anyone who has attended a tech conference will understand the problems that can arise.
Infamously some years ago, or was it just an urban myth, 2.4GHz Wi-Fi was said to not need any form of policing and could cope with many networks, but the day to day evidence is that neighbours networks are impacting on throughput, with the intelligent choice being to switch to the 5GHz band which is currently less crowded.