This is private enterprise, and I am not a government agency. This is not the same as a government forcing me to provide them with a scan of the ID card of everyone that posts here and then using law, police, or military force to control you. Microphones should therefore not be sold unless the person purchasing it registers their identity. Radio equipment, a computer keyboard, tablet computers, anything capable of connecting to a public network must not be sold unless the buyer has registered the purchase with the government. Radio waves must be completely banned. Everything in the electromagnetic spectrum, even the use of visible light must be restricted in case a terrorist uses it for communication.
Because of the speed of spreading it. Pen and pencil is not as fast and as effective as compared to phone. If you say so why do we need to register ourself before able to log in to this website? Why not you open it for ALL so that EVERYONE can make a comment? Even Facebook need user to register. And why not cellphone? This is because by registering the authority can gain more control if someone is using it to do bad thing, and that include detonating a bomb, beside spreading rumors etc etc.