What do you mean "how quickly"? Mass surveillance has been going on for decades. The only new thing is the amount of data the average person has travelling over networks that can be monitored, and the ease of increasing the volume captures.
My favourite example is that in the early 90's, while I was politically active for a period, I met a number of interesting characters, including the ex-editor of a tiny Norwegian communist newspaper. He told me about how he for many years had intelligence agents come up to him on the street to crack jokes about conversations he had with his wife in his own home. While that was outright bugging of his flat, it was part of a many decades long illegal surveillance operation covering pretty much everyone on the political left in Norway (well, to the left of the social democrats who started it) regardless of whether or not they were involved in anything at all.
It was finally rolled up in mid 90's, after the police and parliament had spent several decades ignoring reports from victims of it and insisting that kind of thing didn't happen.