There are drivers (possibly groups of them) that attempt to cause the driver behind them to crash into them.
They do not do this by braking suddenly (brake-checking). But rather, suddenly changing lanes and cutting you off.
What's interesting is that they make sure that they have at least one other passenger in the vehicle (as a witness) but not a dash camera. This is likely to have more freedom to lie about the incident that they attempt to create. Sadly, they also usually have children in the vehicle.
This happened to me three times already. The people that cut me off had ample time to change lanes before I even approached them.
Drive carefully. Always have an out (braking distances, escape routes, safety maneuvers).
These people can say "Hey, I won't call the cops or auto insurance, if you give me X amount of cash..."
Even having dash cam footage for cutting someone off is tricky in court (I imagine).