There are many reasons one may wish to keep the message private and there is no reason to seek explanations through nefarious activities. A very simple and common scenario? Somebody wants to contact a specific person on issues unrelated to topic of the forum and of no interest to other parties, and found that person on this forum. This may be the only known way to contact the person, the only one acceptable to the sender, or the others being inferior for some reason.
Often one has to use the means that are at hand, not the ones designed for the purpose. Cast a stone those of you, who never posted a message on a corridor wall, never left a letter under a windshield wiper, never passed message through a receptionist, and never asked for a call by proxy.
ME20001:
Assuming your request is honest: perhaps somebody here can ping the person, telling them you seek contact? Then other means of contact may be arranged or forum moderators may make an exception. Please do not send posts to the forum just to increase your post count: this will do no good.