This security warning was issued by the State Department. I guess insect repellent isn't the only thing we have to worry about...
Security Message for U.S. Citizens Potential Kidnapping Threat in Cusco
U.S. Embassy Lima, Peru
February 13, 2013
The U.S. Embassy warns U.S. citizens of a potential kidnapping threat in the Cusco area. The Embassy has received information that members of a criminal organization may be planning to kidnap U.S. citizen tourists in the Cusco and Machu Picchu area. Possible targets and methods are not known and the threat is credible at least through the end of February 2013. For the moment, personal travel by U.S. Embassy personnel to the Cusco region, including Machu Picchu, has been prohibited and official travel is severely restricted as a result of this threat.
Review your personal security plans; remain aware of your surroundings, including local events; and monitor local news stations for updates. Maintain a high level of vigilance and take appropriate steps to enhance your personal security and follow instructions of local authorities.
Thousands of U.S. citizens routinely travel to the Cusco region without undue incident. The U.S. Embassy remains confident of the Peruvian governments efforts to ensure the safety of all tourists in the region.
We strongly recommend that U.S. citizens traveling to or residing in Peru enroll in the Department of State's Smart Traveler Enrollment Program (STEP) at
https://step.state.gov/step.
STEP enrollment gives you the latest security updates, and makes it easier for the U.S. embassy or nearest U.S. consulate to contact you in an emergency. If you don't have Internet access, enroll directly with the nearest U.S. embassy.