Snowden was the other big reason that TLS became the de facto standard for every site.

Prior to that, the consensus was that you only really needed TLS if you were dealing with money and wasn't worth the hassle otherwise. You could sniff traffic from Facebook and Twitter easily.

I remember listening to a talk given by an IRS investigator in around 2008 about how they were able to do a sting and shutdown illegal internet casinos. They collected a good bulk of that evidence from clear-text packet captures of gambling sessions and messages. He preemptively answered the question of whether encryption was a hurdle, by saying no one used it.