Two student activists at the University of Maryland at College Park were among 53 people put on a terrorism watch list by the Maryland State Police from 2005 to 2007, the university’s student newspaper, The Diamondback, reported this week.

According to newly released police documents cited by both The Diamondback and the Associated Press, the students were being watched because they belonged to the campus branch of the International Socialist Organization and attended a 2005 campus event opposing the death penalty that was co-sponsored by the group.

The documents reveal that the police were tracking the students — Shane Dillingham, a doctoral student in Latin American studies, and Laura J. Lising, a postdoctoral student and lecturer in physics — “in the event the group engages in criminal activity while involved in their protest activities.” Recent revelations about the watch list — including its existence, who was on it, who authorized its creation, and what use was made of it — have caused an uproar in Maryland.

Although neither of the students faced repercussions for being on the watch list, they now say they worry that the episode could have a chilling effect.

“The government is compiling information on people, not because of what we’ve done, but because of our ideas,” Mr. Dillingham told The Diamondback. “Are students going to want to go organize if they think their name is going to be added to a terrorist watch list?” —Caitlin Moran