Gag Order

Information Request: "Gag Orders" and "Whistleblowers" for 9/11 Truth -- Who, What, Where, Why, When?

Is anybody from the ranks of the frequent 911bloggers able to create a well-written (and sourced) essay that explains "gag orders" and "whistleblowers" and how they influence the search for 9/11 truth?

While writing, please bear in mind that overseas readers are not at all familiar with both terms (and that above Wikipedia links do not necessarily serve to enlighten newcomers about their relevance to the 9/11 truth struggle).

Please explain about whistleblowers and gag orders in a comprehensive way. Simplify as much as necessary, but not more.

So what exactly are gag orders? Who can order a gag? Under which circumstances? For how long? With which consequences in case of breach? Is there a possiblity to overcome such a gag order at all?

What are "whistleblowers"? How many of them are known in relation to 9/11 truth? What are their names? Are they all gag ordered?

I believe if you are able to write such a piece in a way that makes a few stupid Europeans such as myself understand these 2 terms, you'll have a piece that will also enlighten quite a number of U.S. citizens.