I always just assumed that women were paid the same, but I know of several instances where women were not paid the same while doing the same job, with the same, and sometimes even more skill set/experience. That was the case when I was a young adjuster. Everyone was buddy buddy and how much we were each paid was never a secret for long. A lot of the women threw a fit when they found out they were making less than the guys. Especially the ones that were bi-lingual (white, college educated). I think it's more rampant than men assume.
I didn't know today was a thing, and am not making a comment on that part of it, because I honestly don't care and view this much like people on MySpace back in the day spreading the word to "don't buy gas on Tuesday, that'll show 'em!!!" Just pointing out that I always assumed people were paid the same (especially in entry level positions) until I found out that they weren't.