After Katrina, they flocked to New Orleans. After Haiti, they tweeted and telethoned.
But for the most part, more than 50 days after a BP oil rig exploded in the Gulf of Mexico, the celebrity kingdom's not doing much.
Hollywood, usually quick to turn a crisis into a cause, remains relatively removed from the oil spill that began April 20. No rallies. No telethons. No tear-jerking "Oprah" special; no Brad Pitt wearing waders, wiping down oily pelicans. With a handful of exceptions, the celebrity response has been no response at all.
Why? For a town of performers, this particular tragedy may be lacking in drama.
Actor Edward Norton, who recently launched Crowdrise, an online platform that uses social networking to raise funds for a variety of causes, including the oil spill, speculated that the seeming lack of a human element is keeping Hollywood from diving into the crisis.
"I think that at the moment it feels, with the exception of the tragedy of the explosion itself and the loss of life, it feels environmental, not like a human tragedy," Norton told ABCNews.com at the Mashable Media Summit in New York City this week.
There has been talk: Actor Kevin Costner testified at Wednesday's House committee on Science and Technology hearing on Capitol Hill, saying he can provide an oil-separating technology "that is available immediately, a technology that will allow rigs to resume operation and put people back to work." Director Spike Lee urged President Obama on CNN to "go off," while actor Ted Danson proclaimed "no more ocean drilling."
And there has been some action. On Monday's edition of "The Colbert Report," Stephen Colbert declared that everytime he said the word "bing," the Microsoft search engine of the same name would donate $2,500 to oil-spill cleanup efforts. He managed to say "bing" 40 times in the subsequent 20 minutes (best usage: "Bing is a great Web site for doing Internet Web searches. I know that because I Googled it"), thereby raising $100,000 for a new charity, the Colbert Nation Gulf of America Fund. (Notably not the Gulf of Mexico fund because, as Colbert said, "We broke it, we bought it.")