Marriott has says it stopped Ad Service hidden in free wireless.  The free wireless connection inserted lines of code for serving special ads into every Web page a guest visited.

The Marriott’s corporate headquarters said it has investigated the situation and disabled this feature at two New York hotels the Courtyard by Marriott on W. 40th Street as well as the Residence Inn on the Avenue of the Americas.

The company said in a statement that it was not aware of the ad-serving practice and the security of people’s data was not at risk. The Marriott said it did not approve of this practice:

As soon as we learned of the situation, we launched an investigation into the matter. Preliminary findings revealed that, unbeknownst to the hotel, the Internet service provider (ISP) was utilizing functionality that allowed advertising to be pushed to the end user. The ISP has assured the hotel that this functionality has now been disabled. While this is a common marketing practice with many Internet service providers, Marriott does not condone this practice. At no time was data security ever at risk.  We will continue to look into this matter and find opportunities to remind our hotels of Marriott’s high-speed Internet policies.”

Justin Watt a Web engineer with a background in making advertising tools, discovered that every Web page  he visited was being rewritten with new code that could allow a company to inject its own ad banners. “Imagine the U.S.P.S., or FedEx, for that matter, opening your Amazon boxes and injecting ads into the packages,” Mr. Watt said in a previous interview.

The lines of code contained references to RXG which stands for Revenue Extraction Gateway a service aimed at generating money from Internet access points. A company called RG Nets offers the service.  Some hotels have went as far as to charge for internet plus make money on ads.