Since July, when the Journal Sentinel began investigating the mysterious death of a Wisconsin college student in Mexico — and found widespread problems with tainted alcohol, derelict law enforcement and price gouging from hospitals — more than a dozen travelers from across the country have said TripAdvisor muzzled their first-hand stories of blackouts, rapes and other ways they were injured while vacationing in Mexico.

[...] The company's policies and practices obscure the public's ability to fully evaluate the information on its site. Secret algorithms determine which hotels and resorts appear when consumers search. Some hotels pay TripAdvisor when travelers click on their links; some pay commissions when tourists book or travel.

An untold number of TripAdvisor users have been granted special privileges, including the ability to delete forum posts. But the company won't disclose how those users are selected.