Have you guys ever been? It uses a different browser that makes your computer unprotected but also makes you invisible from feds.
The deep web represents a gargantuan part of the internet which is not accessible through regular searches via google or other search engines.
Searching on the Internet today can be compared to dragging a net across the surface of the ocean. While a great deal may be caught in the net, there is still a wealth of information that is deep, and therefore, missed. The reason is simple: Most of the Web's information is buried far down on dynamically generated sites, and standard search engines never find it.
What lies beneath the surface is a who's who of hackers, scientists, drug dealers, astronomers, assassins, physicists, revolutionaries, Government officials, Police, Feds, terrorists, perverts, data miners, kidnappers, sociologists, etc. As you can tell, the party goes across the entire moral spectrum.
Here's a Screenshot of the Hidden Wiki: