Doing such is a crime and could - and sometimes does - get people killed.
For those who have not grown up in an environment where classified documents/information was the rule of the day, the following may be of interest.
In the most simple of terms, anything that is deemed classified relates to National Security. There are strict rules for handling such information. AND, there are laws relating to such.
For example, there is 18 U.S. Code § 798 - Disclosure of Classified Information. Should you by chance actually read this law you will see that it not considered a laughing matter. There are other laws on this as well - all have potential jail time associated for violation.
These laws are there to protect our Nation and people who serve us all. Unauthorized release of classified information, as restated from above for reinforcement, can - and does - get people killed.
Most of us, of course, have never even seen a classified document. So, how does one tell if something is classified or not? Well, it can get tricky sometimes.
The following few pictorials offer what such documents are supposed to look like - at a top-level view only.
At the highest level there are detailed background checks, personal interviews by security specialists of your family, your current and former employers, your friends, your friends' friends, and beyond. Often, polygraph tests are involved. And, it takes quite a while for the higher level of clearance to be granted.
How does one lose their clearance? Aside from the obvious situation of mishandling classified information, this can happen in a number of ways.
For example, this happens when you no longer work for the organization that required you to have a clearance in the first place. Also, if you no longer have a verifiable "Need To Know" - and a longer list, of course. In any case, should one of these occurrences happen, security protocols demand you have your clearance removed.
So, when we read or see in the media that a "classified document" was hacked and released, one has to wonder. If the media knew that the information was classified and released it anyway, the responsible media is guilty of a crime. This means that ANY reporter (or anyone else) who has released classified information for any reason has violated the law - as well as the reporter's "source".
Why have there been no in-depth investigations and no prosecutions?
And, when government officials, past and present, openly admit to mishandling classified information, why have there been no in-depth investigations and no prosecutions?
And, EXACTLY, why do some former government employees still have high level security clearances - or, any at all - with no discernable "Need To Know"?
Are we all not "Equal Under The Law"?