Looking past the cost, it also used to be a huge hassle. If I wanted to know what you were doing, I'd have to hire 6 guys sure, but I'd also need to manage them. Plan out their shifts, handle payroll, and their internal disputes. The practical reality of surveillance meant it HAD to be a conspiracy. The risk of someone talking was huge.

Now it's easily hidden. Somebody can monitor you just by accessing information systems without the people collecting the data even knowing. You can now do the surveillance alone, no pesky accomplices needed.