The high school has a long tradition of students running naked through the campus during the end of the school year to celebrate the last week of school before summer, the San Jose (Calif.) Mercury News reported Thursday.
This year, though, students have started a little earlier than normal.
"In my six years at Paly, it never has happened on the first day of school," said Principal Kimberly Diorio, who was formerly the assistant principal at the school.
She said the streaking creates a negative environment at the school and in the past "consequences may not have been applied consistently nor made clear to students, which has only made the situation worse over time."
"The consequences from this point forward will include suspension from school and a conference with our Palo Alto Police Department School Resource Officer," she wrote in a letter to students.