The Office of Student Life has forbidden students in upperclassmen Houses from hosting overnight guests they meet through the online hospitality exchange network CouchSurfing.org, Mather House Master Michael D. Rosengarten and Adams House Master John G. "Sean" Palfrey ’67 confirmed yesterday.

Dean of Student Life Suzy M. Nelson was not available for comment.

Couchsurfing is a term that refers to the practice of utilizing a large network of participating hosts and travelers to find places to stay while traveling. CouchSurfing.org, the website behind the phenomenon, connects travelers with hosts willing to offer up their couches for one or more nights.

An e-mail sent Friday to all Mather House residents stated that "inviting guests whom you meet through ‘couchsurfing.org’ is not permitted." According to Rosengarten, these restrictions apply to all upperclassmen Houses.

According to Palfrey, although students in Harvard Houses are forbidden from hosting couchsurfers, they are still allowed to use the website, and as a result are still allowed to find hosts and connect with other couchsurfers in their area to share their couchsurfing experiences.

Freshman proctor Jason L. Outlaw said that freshman dorm proctors have not been made aware of similar policies in the freshman dormitories.

Since its founding in 2004, CouchSurfing.org has attracted over two million members and has facilitated over 2.5 million "successful surf or host experiences," according to its website.

Several Harvard-specific groups are registered on Couchsurfing.org with a stated mission of connecting current Harvard students, alumni, and affiliates. The two largest Harvard groups currently hold 94 and 44 members each. However, the total number of Harvard students who use Couchsurfing.org to find and offer temporary hosting may be much greater, as many students who currently use the service opt not to join a particular group.

Rosengarten’s e-mail to Mather residents warned that "meeting and hosting guests" through couchsurfing "could compromise the safety of House residents." Although CouchSurfing.org assures on its website that it provides "a safer way to meet people than you might think," isolated incidents still occur. The website’s message boards include many individual accounts of alleged assault. In 2009, the rape of a Hong Kong couchsurfer by her host in England made headlines.

Rebecca H. Kwan ’14, who has used CouchSurfing.org to both host and find a place to stay, said that although she understood the concerns of Harvard administrators, she considered use of the service "all right as long as your dormmates or your roommates are OK with it."

Kwan, who hosted a female couchsurfer from Israel in her Matthews dorm room earlier this semester, said she chose to volunteer her couch as a way to give back to the couchsurfing community, which helped her find a place to stay when she was traveling abroad.

"I [couch]surfed when I needed a place to stay in Australia," Kwan said. "I think it’s a really good experience. The people you meet when hosting are amazing and their experiences are so incredible."