It can actually be quite easy to amass loads of points without ever driving dangerously. For example the quickest (and apparently most obvious) way to get from B&M in Stowmarket to Asda, at the other end of the town, is to turn right onto the main street and then left off it at the other end.
Unfortunately though there's a (not particularly obvious) 'No right turn' sign at the first junction and a 'No left turn' one (which also doesn't exactly leap out at drivers) at the second one.
When the old bill have been stopping drivers who've ignored those signs, there have been plenty of people who've acquired 6 points on their licence, in the space of a couple of minutes, while driving perfectly safely.
They're now using cameras from time to time at those two junctions. So someone who travelled via the most direct route from B&M to Asda twice per day could acquire 12 points in a day. If the tickets weren't sent out until the end of a working week, they could end up with 60 points on their licence without ever putting anyone's safety at risk.