At work, security checks and locked doors are becoming routine inconveniences for biomedical researchers who work with animals.
But as animal-rights extremists have escalated their attacks, some universities have extended these protections to scientists in their homes.
After members of the Animal Liberation Front vandalized cars and harassed researchers at home last year, the Oregon Health & Science University began increasing police patrols, installing cameras at some homes, and counseling scientists not to debate protesters.