Then we are all minors because I don't see how we are allowed of full responsibility. For example, we don't seem to be allowed to own and use drugs.
And how does having sex with a person under the legal age of full responsibility (which may not come until like 35 when you're allowed to apply for certain political positions in some jurisdictions) allows a third party to tweet away the details of your sex life?
I'm all for the freedom of speech, but anyone who does that is a very very bad person. You might have a right to tweet about other peopes' sex life without their consent (if we aim for absolutely free speech), but using that right marks you a very bad person indeed.