These CIA videos that were posted on Facebook for some reason explain how stalking was done in a pre-digital age. As Jalopnik states:
The key seems to be, of course, don’t let the mark see you. According to the CIA way, the best way to accomplish that is to work in a team, in this case of three cars. There’s lots of map-reading involved, extrapolating most likely exit routes of your target, and constant radio communication between the pursuing cars.
The good news is today we have many advantages, since almost all of us owns a small handheld device with both a constantly-updating map and a 2-way radio. The trick is convincing several stalker-minded friends to help you out, but I guess that’s what Craigslist is for. Even with nice, creepy dedicated stalker pals and 21st-century equipment, there’s still some fundamental rules to effective, undetectable car following, and it’s great we have such resources available, especially if you’re just working with what you learned from watching Jack Nicholson smash that taillight in Chinatown.
Kids these days have it so easy.