More than 200,000 schoolchildren are paddled, spanked or subjected to other physical punishment each year, and disabled students get a disproportionate share of the treatment, according to a new study. Most states prohibit corporal punishment in public schools, but 20 do not. The two watchdog groups that collaborated on the report, Human Rights Watch and the American Civil Liberties Union, are urging federal and state lawmakers to extend the ban nationwide and enact an immediate moratorium on physical punishment of students with disabilities.