Effective celebrity activists use their fame and fortune to bring attention to important issues and to give credibility to representatives of social movements. Internationally known celebrities can help expose and highlight problems that would normally get little or no news coverage without their involvement.

George Clooney’s recent arrest for protesting in front of the Sudanese embassy in Washington, D.C. is a perfect example of this.

But does celebrity involvement really make any difference in what people care about? In a society obsessed with celebrity worship and showbiz, the answer is a resounding yes. The problem isn’t that famous people shouldn’t speak out about politics or social issues. The problems begin when celebrities try to speak for the people they are trying to help. This is especially true when they don’t actually belong to the group they claim to represent.

Every citizen can and should have the right to publicly take up issues of social welfare, injustice and matters of war and peace.

We are social animals. The average Joe doesn’t have the time or the resources to devote to such causes, but millionaire celebrities have plenty of money and time on their hands. When a celebrity throws their political or cultural capital behind a movement much larger than themselves, the success or failure of that movement can become entwined with their personal reputation.

The heavier the capital, the more inseparable they become from the cause, in many cases. Celebrities might have the noblest of intentions, but they can also end up having a negative effect on the issues if they aren’t careful.

John Lennon is one example of a celebrity who was able to successfully brand himself as a “peace activist” by simply supporting the idea of peace without giving any definitive answers about how to achieve it or what it meant. His reputation was enhanced among progressives and anti-war supporters, but his political opinions (naïve as they were) got him into hot water with the U.S. government, which was heavily invested in the Vietnam War at the time.

Traditionally, musicians have been at the forefront of activist causes, in the folk traditions of union organizers such as Woody Guthrie, Joe Hill and Pete Seeger. More recent examples of musicians bringing awareness to social issues include George Harrison’s Concert for Bangladesh in 1971, Bruce Springsteen with the No Nukes concerts in the late ‘70s through to LIVE AID, FARM AID and the TIBETFREEDOM concerts in the ‘80s and ‘90s. Pop stars such as Bob Geldof, Willie Nelson, Neil Young, Dave Matthews, Paul McCartney, Erykah Badu and Bono have been high-profile champions of many worthy causes. The LIVE AID concert on July 13, 1985, and the subsequent LIVE 8 shows in 2005 are two particularly notable examples of successful consciousness-raising regarding global sustainability issues — although they failed to bring us any closer to actual solutions.

Entertainers like the late Danny Thomas used to be a rarity. A true visionary in the field of celebrity activism, he helped establish St. Jude’s Hospital in Memphis, Tenn. in 1962. Thomas’s daughter Marlo and her husband, Phil Donahue, still work to raise money for the internationally recognized children’s health facility and nonprofit, Medical Corporation.

From the early ‘50s until 2011, Jerry Lewis served as national chairman of the Muscular Dystrophy Association (MDA). He started hosting telethons to benefit MDA in 1952, and from 1966 until 2010 he hosted the annual “Jerry Lewis MDA Telethon,” now called the MDA “Labor Day Telethon.” In August 2011, it was announced that Lewis would no longer host any telethons due to his declining health.

Harry Belafonte was instrumental in promoting civil rights legislation in the early ‘60s. French actress Brigitte Bardot retired from Hollywood in 1974 to devote all her time to animal rights causes. Audrey Hepburn supported animal rights, UNICEF and the United Nations.

Today, celebrity activists are a dime a dozen. Angelina Jolie is following in Hepburn’s footsteps. She and Brad Pitt are outspoken activists who volunteer their time and donate money to many worthwhile causes. Jolie is also a goodwill ambassador to the U.N. as a member of the Council on Foreign Relations, the international foreign policy think tank.

Tennis legend Andre Agassi established the Andre Agassi Preparatory Academy, a charter school for at-risk children in his hometown of Las Vegas, Nev. Now considered one of the best prep schools in the country, Agassi and his wife, fellow tennis legend Steffi Graf, have donated more than $35 million to the project.

Ben Affleck, Oprah Winfrey, Leonardo DiCaprio and Sean Penn are further examples of celebrities who have taken a public stand on important issues, and in some cases they’ve experienced career setbacks because of them.

Ashton Kutcher’s anti-sex slavery campaign is a recent example of celebrity activism gone wrong. He made his case with poor data, which resulted in a public awareness campaign that wrongly identified the root cause of human trafficking as essentially a moral issue, and in the end Kutcher trivialized and misinformed people about an important cause.

A celebrity activist is an asset only insofar as he or she is respected. If not, the celebrity becomes a liability. Sometimes celebrities would do better to just write a check and shut the hell up.

Celebrity interest in Africa has become something of a cliché these days, thanks to Angelina Jolie’s adopted daughter and overhyped events such as Madonna’s adoption of a child from Malawi several years ago. The Arab Spring and the Kony 2012 controversy have certainly kept African issues in the headlines lately. And now, thanks to his arrest last month for protesting outside the Sudanese embassy, we can add George Clooney to the list.

Unfortunately, as pointed out by Sudanese writer Nesrine Malik in British daily “The Guardian,” the U.S. media’s preoccupation seemed not to be with the suffering of the Nuba mountain people (the cause Clooney is advocating for), but with fawning over the virtues of celebrity activism. Malik sarcastically referred to Clooney’s replies to reporters as “beauty pageant contestant responses to what is actually going on in Sudan.”

To many Sudanese activists, celebrities like George Clooney come off as well-meaning, but ultimately irresponsible and even potentially destructive to the cause. The problem with Clooney’s selective approach to humanitarianism is that it implicitly perpetuates the idea that genocidal acts are carried out by other governments, never by ours. Most people are unwilling to accept that the economic policies of our own government are (arguably) responsible for most of the world’s suffering.

George Clooney should be commended for his efforts to bring awareness to the plight of the people he claims to support, but he also needs to be careful when he tries to oversimplify matters for the general public, and he needs to consider that his humanitarian work might appear to be self-serving to some people. It’s a fine line, for sure.

His arrest can only help his image in any case (at least among the Hollywood elite), and if that’s what it takes to bring attention to the situation in Sudan — more power to him. The world needs more high-profile celebrity activists to challenge mainstream power structures — as long as they’re sincere and intelligent about it.