From
New York Times: The earliest episodes of Sesame Street are being made available on DVD, but the NYT notes Volumes 1 and 2 carry a rather strange warning: 'These early 'Sesame Street' episodes are intended for grown-ups, and may not suit the needs of today's preschool child.' So why are they unsuitable for toddlers in 2007? Well, in the parody 'Monsterpiece Theater,' Alistair Cookie - played by Cookie Monster - used to appear with a pipe, which he later gobbled. 'That modeled the wrong behavior,' explained a Sesame Street executive producer, adding that 'we might not be able to create a character like Oscar [the Grouch] now.'