Crimes committed against individuals because of their race, religion, ethnic origin or sexual orientation appear to be increasing in the United States. Whether the offenses are homophobic slurs, anti- Semitic vandalism or racially motivated assaults, experts say that bias-motivated crimes have an especially devastating effect on society at large, as well as on individual victims. To combat hate crimes, more than half the states have adopted laws providing longer sentences for certain offenses when they are motivated by specified types of prejudice. But some civil liberties advocates say the laws threaten freedom of speech. Two state supreme courts threw out such laws last summer. Now the U.S. Supreme Court has agreed to review one of those decisions, setting up a major legal test between civil rights and civil liberties.