Hard to pick just one..
Make it against the law, with stiff penalties, to have invasive/obtrusive advertisements, spam e-mail, and unsolicited calls/mail.
Or make it so you can't have tiny little disclaimers, fine print, or rapidly spoken disclaimers on the radio.
Pretty much anything that makes me want to go up to someone does it and savagely beat them while yelling swears at them for being so stupid.