There is no single traffic law "here in the States." Each state has its own vehicle code and though they are similar there are significant differences in the details. Your statement above does not reflect the traffic code in California or in most of the states in which I've lived (haven't checked Mass.).

The California Vehicle Code prohibits entering an intersection on a red light, but there's no requirement to clear the intersection before it turns red. There is a prohibition against entering an intersection when congested traffic would prevent you from exiting it - i.e. to prevent a gridlock situation, but if traffic is flowing smoothly you can legally enter the intersection just before the light turns red. Those who then get a green light are required to wait for any traffic that entered the intersection legally to clear it before proceeding.

Technically I'm sure the riders in both the Florida ride and the one in Toronto are violating the local codes on red lights since many of the riders are entering intersections after the light changes to red. OTOH, these are regular rides and I'm sure the local authorities are well aware of them and have apparently decided not to enforce the letter of the red light law - probably because they don't see it as a safety problem. I know in some towns the police have met with cycling clubs and indicated that they would not issue either red light or stop sign citations as long as the lead riders obey the signals/signs and the rest follow as a single group.