"We look forward to working with you to ensure that only age and culturally appropriate programmes air on PBS, which is a mainstay that millions of parents have come to rely upon over the past 35 years, " the letter addressed to PBS president Pat Mitchell added.

BBC: US politicians attack HIV Muppet

In the independent day and boarding school arena, Mitchell and NAIS President, Pat Bassett, are noted authorities on affordability.

FORBES: Affordability of Independent Day and Boarding Schools