The message might "disappear" after a few seconds, but at that point FB may have already extracted the information they want from it, information they will use to further their business.
Assuming users want some sort of privacy, from whom is it that they want their messages to remain "private"?
Will there ever be options in FB "privacy settings" such as:
[ ] Do not share with Facebook
[ ] Do not share with advertisers, political campaigns, etc.
Absurdity aside, the mere feasibilty of this is itself debatable.
Do users want their messages to remain private from companies like Facebook?
How about from FB's clients, e.g., advertisers, political campaigns, hospitals, etc.?
How about from the rest of the general public?
We now know as confirmed by FB that this user data has been shared for years. Perhaps FB can argue this was "informed consent".
However users can change their minds in light of more information. They should be able to revoke that consent going forward.
Will all that "leaked" user data FB has intentionally shared self-destruct after some period of time? Unfortunately, no.
It seems to me that, in the main, the parties that have the greatest incentive to monitor users messaging are in fact companies like FB and their clients.
They have a financial incentive that is in the aggregate far greater than any individual (petty criminal, etc.). Collecting user data has become their business. "It is literally just what we do." Period.
Finally, thanks to the explosive growth of single websites into vast monopolies like Facebook that extend their reach into nearly every corner of the internet, they, the companies behind these websites, are in the best position to do it.
It should be self-evident but maybe needs to be restated: These companies cannot protect the user from the company itself. The amount of trust required of the user depending on these websites is simply mind-blowing (from the perspective of someone who has lived in times when no such trust was necessary).
Thats only an opinion. I respect any disagreement and welcome karma subtraction as a means to express it.