why not block the individual computer regardless of the users who can lie about there identities or intentions?

Edit Subject

each and every individual personal computer have its very own and unique signature in order to store cookies, so why not block that single computer all together. look, if you are getting emails or notifications and block them you are only blocking that name which isn't real to begin with if they are less than honest. the point is that each message still comes from the same single computer of, let's say, a scammer or solicitor of funds if they have targeted you, but they already have your profile and you marked so they simply change their name and try again to get you to let them in. the point is that their computer has to be identified somewhere and recognized in order to operate on the web, so why not block any and all messages regardless of how numerous or diffidently named from that signature all together. you can not always identify the real person, but you can the individual computer, so why not block that single signature all at once? this ain't rocket science goddammit! i think it would prove very surprising and eliminate several names from random bull shit all at one time, and if it affects something the user wants then they will at least know who they are dealing with and who's playing them as a fool if they choose to opt that signature back in. does this not make perfect since or am i just not supposed to blab that there is truly is no computer hidden on the web, but rather just the names on them?