Burnett Ranches, Ltd. v. Cano Petroleum, Inc., 289 S.W.3d 862, 871 (Tex.App. --- Amarillo 2009, pet. for rev. filed):

Third, the trial court excluded, as unauthenticated, a writing and recording from Cano's website. Counsel for the Burnetts attested that the former was a “true and correct copy of Cano Petroleum's Environmental Overview printed from its website” and the latter was “a true and correct copy of excerpts from AMEX TV Interview of S. Jeffrey Johnson obtained from Cano's website.” So identifying the former was sufficient to establish its authenticity in Daimler-Benz v. Olson, 21 S.W.3d 707, 717 (Tex.App.-Austin 2000, pet. dism'd w.o.j.) (wherein the affiant attested that the documents were true and accurate copies of the originals). Yet, the affiant here did not establish that the website from which he secured the document was actually that of Cano. Indeed, most anyone with knowledge of the internet may be able to create a website. And, while it may be arguable that most information found on the internet is what it purports to be, we cannot simply assume that all of it is. Also missing from the affiant's comments were statements revealing that he knew or recognized the voice of Jeffrey Johnson and that the voice excerpts captured from the website were actually those of Johnson. Consequently, we cannot say that the trial court abused its discretion in excluding the items as unauthenticated. See Amis v. State, 910 S.W.2d 511, 516 (Tex.App.-Tyler 1995, writ ref'd) (holding that the recorded message was not properly authenticated since the witness attempting to authenticate it could not conclusively identify appellant's voice).

The court correctly concluded that the authentication was defective.  But, since websites can be "spoofed," a question arises as how to prove a website up, short of a deposition of the website owner or webmaster.

Comments from IT professional on how to "prove up" a website:

I would think that you would have to look for the presence of a third party verification indicator.  See the following.

http://www.buzzle.com/articles/3rd-party-website-verification-services-the-ultimate-online-conversion-strategy-and-solution.html

http://www.trust-guard.com/

I don’t know how it would hold up in court, but you can also use a WHOIS search to determine where a site “should” be, and who owns it, etc.

http://www.whois.net/

If you are investigating a site I think you might be out of luck without a verification seal…and not even sure that would hold up based on the case you sent.  Interesting question though…seems like you might be able to post whatever the heck you want and not be held accountable/liable for it, but that doesn’t make much sense, especially with how the gov’t is cracking down on anonymous bloggers, etc.