If you are of a certain age, you may recall an animated cartoon series titled Peabody’s Improbable History, which involved a clever machine (called a wayback machine) that could transport people (and dogs) back in time. The same animators turned out the delightful Rocky (the squirrel) and Bullwinkle (the moose) cartoons.
There’s a similar “machine” on the web, which allows us to view websites as they were in the past. It’s also called “the wayback machine” and is available here: http://www.archive.org/web/web.php.
I don’t know if these web page “snaphots” are admissible as court evidence, but I’m sure that investigators of all sorts use “the way back machine”.