NEW YORK — Last year, someone edited the Wikipedia entry for the Sea World theme parks to change all mentions of "orcas" to "killer whales," insisting that this was a more accurate name for the species.

There was another, unexplained edit: A paragraph about criticism of Sea World's "lack of respect toward its orcas" disappeared.

Both changes, it turns out, originated at a computer at Anheuser-Busch, Sea World's owner.

Dozens of similar examples of insider editing came to light last week through WikiScanner, a new Web site that traces the source of millions of changes to Wikipedia, the popular online encyclopedia that anyone can edit.

The site, wikiscanner.virgil.gr, created by a computer science graduate student, Virgil Griffith, cross-references an edited entry on Wikipedia with the owner of the computer network where the change originated, using the Internet protocol address of the editor's network.