Few things are more certain to pique the curiosity of Internet data hounds than the sudden disappearance — temporary or otherwise — of a popular website.

As of late afternoon on Friday, movie data hounds were becoming more and more curious about the sudden absence of Box Office Mojo, whose address, boxofficemojo.com, had been redirected to that of its parent, the Internet Movie Database, or IMDb.com.

Box Office Mojo is, or was, a premiere compiler and analyst of movie box-office information, both domestic and international. Started in the late 1990s, it was sold to IMDb.com and its parent, Amazon, but continued to operate as an independent site.

Neither Brandon Gray, who long ran the site but left several years ago, nor Ray Subers, who has been operating it lately, responded to queries. Queries to Amazon representatives also drew no immediate response.