If you tend to drive too close behind people, you will see this happen a lot - people really don't like getting involved in highway pile-ups, so it's better to

If you tend to drive too close behind people, you will see this happen a lot - people really don't like getting involved in highway pile-ups, so it's better to give you a brake check than to wait until it actually matters. However, it is very rare for people to "brake check" you unless you do that.