The policy is called "day-fines," according to the BBC, and it works like this: the government estimates how much spending money the perp in question has each day depending on their declared income. They divide this number by half and then figure out how many days worth of half-spending cash the person is liable for, depending on the scale of the crime. Such fines are applied to everything from speeding to shoplifting to insider trading. The days are capped at 120, but the size of the fines are not.
It's rare, but not unheard of for wealthy Finns to pay thousands for going 15 miles per hour over the speed limit. The Atlantic reported on a Nokia executive who was fined $103,000 for going 45 mph in a 30-mph zone on his motorcycle. Recently, Finnish businessman Reima Kuisla was finned $56,644 for traveling 65 mph in a 50-mph zone. Kuisla's take-home pay is around $6.8 million a year.
Rich Finns are crying foul, but everyone in the country is subject to the same fine structure. Here in the US, such speeding tickets would, at most, cost a few hundred dollars and be applied to rich and poor alike. However, the European "day-fine" model might be more fair and lead to safe roads. In America, traffic fines tend to disproportionately affect disadvantaged drivers, while studies show rich drivers tend to drive less ethically. If the rich had to feel the bite of a traffic fine that the poor do they may be more apt to follow the rules of the road.