What if you're a stalker though? You can target a person by his/her e-mail address or phone. Facebook used to allow you to target as little as 20 persons. I don

What if you're a stalker though? You can target a person by his/her e-mail address or phone. Facebook used to allow you to target as little as 20 persons. I don't know if this still holds true. So you enter 19 fake e-mails and the one you're interested in targeting. So eventually only a specific person will see your ad.