Protesters in black masks started fires and damaged property in an attempt to stop controversial speaker Milo Yiannopoulos from speaking at the University of California-Berkeley in February.

It is situations like those that have U.S. senators on the Judiciary Committee discussing free speech on college campuses.

In the past several months, universities have canceled speakers after threats of violence.

Many of the speakers have been conservative, prompting concern among Republican senators about universities potentially silencing controversial voices.

“That is an open invitation to discriminate based on viewpoint,” Judiciary Committee Chairman Chuck Grassley, R-Iowa, said.

Sen. Dianne Feinstein, D-California, said she’s worried universities lack equipment and security to protect students from violence at speeches.

“I do believe that the university has a right to protect its students from demonstrations once they become acts of violence,” Feinstein said.

Zachary Wood, a student at Williams College in Williamstown, Mass., testified in front of the committee.

He said it is important to have your beliefs challenged.

“Instead of nurturing thoughtful debates of controversial topics, many college educators and administrators discourage free debate by shielding students from offensive views,” Wood said. “Yet one person’s offensive view is another person’s viewpoint.”