A student faces disciplinary action after two people threw green whipped cream pies at New York Times columnist and author Thomas L. Friedman as he began an Earth Day speech at Brown University.

A video of the Tuesday incident posted on YouTube.com shows Friedman telling the audience, "It's great to be back here at Brown," shortly before Margaree Little, a senior English literature major, and an unidentified man storm the stage.

Friedman managed to avoid most of the cream, although his shirt and the back of his head were splattered and he appears to slip on cream on the stage. He left the stage to clean himself off before resuming his speech.

He said Friday he was not pressing charges.

"I'm leaving it for Brown to decide what kind of values they want to uphold on their campus," he said.

Little, who's scheduled to graduate in December, said she was undergoing disciplinary action by the dean's office and expulsion was "not off the table."

She declined to identify the man who was with her or to say whether he was a Brown student.

Little, 22, said Friedman's brand of environmentalism is a "sham" because she believes he supports things like biofuels that reduce the availability of food and displace thousands in Haiti and other developing nations. Friedman, an environmentalist, has written about taking a careful approach and ensuring biodiversity is preserved in areas where biofuel crops are grown.

Little also said she and her co-pie thrower wanted to open up a dialogue about what it really means to have free speech on an elite college campus like Brown.

She said they considered passing out fliers or preparing questions to ask Friedman during a question-and-answer session, but ultimately decided to take a more significant step.

"I think it was successful in that those conversations are happening now in a pretty engaged way," she said.