What metaphors are used in Snow Crash by Neal Stephenson?

Snow Crash refers to three separate things. A computer system snow crash is caused by an error that causes even the signal to the monitor to crash, resulting in a screen of static that resembles snow. The Snow Crash computer virus is represented by a bitmap, that when transmitted into the optic nerve of a hacker, will cause the brain to crash. The Snow Crash drug is a delivery mechanism for the Asherah virus developed by L. Bob Rife's organization.