I agree that a lot of people follow way too close. 1 car length per 10MPH is a good rule. So giving at least 100ft on the highway is appropriate. But brake checking is different. The assholes who do it pull in front of you and then slam on their brakes. If they do it too aggressively there is literally no time to adjust to an appropriate distance because they merge into your lane and immediately brake. Causing an accident because of brake checking like this is 100% the brake checkers fault.