On the Halo series page at Wikipedia, an edit originated from Sony Computer Entertainment casts aspersions on Microsoft's Halo 3. In the Halo 3 section of the Halo page, Sony added "(Halo 3) wont look any better than Halo 2." (See the first and second story images attached below.) Since then, the Halo page has been corrected and locked from further vandalism.
The WikiScanner discovery is also reported on Wired's 'Threat Level'. (See Alternative Sources.) The report and IP address have been checked by Wired senior editor Kevin Poulsen, (i.e., see the third attached image for Poulsen's comments; "Sony insults Halo 3" is the second report after the Walmart report.)
Finally, the forth and last image was taken from a 'Whois' search at the RIPE.net database for "188.8.131.52", the IP address recorded by Wikipedia as having edited the Halo page. The query shows that 184.108.40.206 is registered to SCEE (Sony Computer Entertainment Europe) Liverpool Studios in Great Britain. The result also shows the studio's physical address, phone number, and email address.