About 50 students from the Archbishop Wood High School protested Thursday outside the Planned Parenthood clinic in the Philadelphia suburb of Warminster, about a mile (kilometer) from the school.
The students received a boost to their grade in a class on morality. Religion teacher June Littel said the extra credit was meant to reward students ``for giving of their time.''
At least one student, Courtney Morris, 17, said she would have picketed anyway.
``We just wanted to come out here because that's our faith,'' she said.
Linda Hahn, chief executive officer of the clinic, said the protesters made patients uncomfortable, though none were there for abortions. The clinic does not perform abortions on Thursdays.
``Anyone who would spend their time harassing people who come for medical attention, it's ludicrous,'' she said.