France has decided to use cameras at the Olympic games with software that will scan the images looking for "suspicious activities".

We can't count on the software in the system to limit the effective level of surveillance, because more analytical capability could be added later. The only limiting factor that people can count on to prevent violation of their privacy is the capability of the hardware sensors (cameras, in this case). As people pointed out, that capability might be sufficient to enable the system to recognize and track people.