A recent New Jersey District Court case established precedent that, when it comes to e-discovery , websites should be treated like all other electronic files.  Under this ruling, failing to produce a website that existed at the time the corporation was sued can be grounds for sanctions.  Chad Weiner, of the Milwaukee firm Quarles & Brady, recommends that all corporate litigation hold policies have a mechanism in place to be sure that the website is preserved just like all other corporate documents.

Source: E-Discovery Bytes

Check out the Wayback Machine for archived versions of popular sites.