The FTC claims that AT&T throttled data plans for at least 3.5 million unlimited data holders, it doesn't mean there are 3.5 million plans in total. Even if it were true, 3.5 million is still a big number if that was the entire population but it isn't. It is only the portion that has been throttled.
I am an unlimited data holder and have never been throttled, hence I am not included in that 3.5 million figure. In other words, there are a ton of people that got throttled. But there are an even bigger ton of people that never reached 5GB of data and were never throttled. If 3.5 million users were throttled, there's gotta be a ****** ton more people that have the unlimited plan and were not throttled.