[eleventyseven]

Doesn't sound like you were breaking the law there. If you aggressively tailgated or were harassing drivers who didn't follow the law or your expectations, that road rage is vigiliantism.

If you publicly shame an alleged criminal within your free speech rights, you're not a vigilante. If you cross into harassment or stalking in your attempt to take the law into your own hands, that's a vigilante.

Deciding who can and can't use a mobile phone? That's part of the monopoly of violence that defines the government's exclusive power, just like imprisonment.