It's not something that UC Berkeley wants to really talk about and all administrative staff declined to go on camera. Many people we spoke to on campus have already received threats as well.
Across the UC system, and on the Berkeley campus in particular, there's always a threat for anyone conducting animal research.
"The people making threats like this have a gut emotional reaction to, but they don't know anything about it," says one Ph.D. student who agreed to talk only if we did not reveal her name. She is not one of the 24 researchers to receive phone calls or e-mails threats this past year, but she works with them.
"Names of people in labs have been targeted for potential acts against them."
Names appear on the internet, among other places along with addresses, phone numbers, and other information. Not just researchers, but anyone associated with projects.
Protest groups have even encouraged harassment against companies hired to do construction at U.C. Berkeley's new center for biomedical and health studies.
Amanda Carson Banks runs a non-profit that is tracking such attacks. UC Berkeley reported dozens of them in the past year, but the movement has a rich history.
"This is a problem that is widespread throughout California and the United States. It's a problem that is not just on UC campuses, but on hospitals doing medical research in California and private research institutes and on universities as well," says Banks.
Protestors have chained themselves to campus doors and even took over a crane in one misguided action that had nothing to do with animal testing.
"It's a significant problem because it really does kill researchers and really make them feel threatened, so they are finding it difficult to complete their work and it threatens the health of all of us, because without these researchers doing this work, we all lose," says Banks.
Until last weekend, their protests had remained mostly non-violent. Now, it appears the rules of engagement have changed.
"I don't think it's founded on a lot of logic or reason," says the CAL student we spoke to.
More than just the FBI is involved. Local police, along with campus police, are involved. In fact, there have been arrests earlier this year for protests in El Cerrito, where protestors were brought in but no charges were filed.