Harvard Law students are taking Big Law to task yet again—this time over representing Exxon Mobil — which is headquartered in Irving, Texas — in climate change litigation.

A group of 30 first-year law students on Wednesday disrupted a recruiting reception hosted by Paul, Weiss, Rifkind, Wharton & Garrison, which has been representing the oil giant in a series of lawsuits tied to climate change. After unfurling a banner that read #DropExxon, the students spent 15 minutes chanting and singing before leaving the reception—held at a restaurant near the school’s Cambridge, Massachusetts, campus—and joining other climate change protesters outside.