The owners of Backpage.com on Monday shut down the “adult” section on the online classified advertising site, just hours after a U.S. Senate committee released a report that found the site knowingly aided users in posting ads for prostitution and child sex trafficking, the Chicago Sun-Times is reporting. The 53-page report issued Monday by the Senate Permanent Subcommittee on Investigations is the most scathing probe yet of the controversial online marketplace built by the founders of the Village Voice.