When I was at Berkeley during the 1970s, college students were encouraged to carry their keys jutting out from between their fingers a night -- and never go out alone. The keys between one's fingers turns a human hand into at the least a dog paw, if not a tiger paw. Dog scratches, I can attest, are to be avoided. Such is what a group like Women Against Rape encouraged women to do -- and encouraged their boyfriends to do so when out with them. (Oh, yes -- never go out alone at night and don't get drunk).
Rapists are cowards; they don't want to get hurt. The keys are obvious. College textbooks and laptop computers make good defensive weapons.
