The YouTube era has produced a few Catholic stars, priests whose performances have inspired scores of web surfers to pass along emails full of grief or glee.

Who can forget "The Barney Blessing," with the priest who traded his vestments for a purple dinosaur suit before the final prayer of a Halloween Mass? Then there was the trendy priest whose loopy dance to the altar, accompanied by trumpets and drums, inspired comparisons to Prince Ali's arrival in the Disney classic "Aladdin."

But these were tiny tremors compared with the online earthquake that followed Father Michael Pfleger's sermon in which he pretended to be Hillary Clinton, sobbing because of her losses to Sen. Barack Obama.

"She just always thought that, 'This is mine. I'm Bill's wife. I'm white,' " said the priest, speaking at Trinity United Church of Christ in Chicago. "Then out of nowhere came, 'Hey, I'm Barack Obama.' And she said, 'Oh damn, where did you come from? I'm white. I'm entitled. There's a black man stealing my show.' ''

It's natural to watch these cyber spectacles while muttering, "What were they thinking?" The answer is quite simple, according to Father John F. Kavanaugh of St. Louis University. Like many preachers before them, they fell for the temptation to "preach to the choir," their listeners who already agreed with them.

"You're supposed to be a messenger. You're supposed to be the person who brings people the Good News," said the Jesuit, author of "Following Christ in a Consumer Culture" and other books on faith and ethics. "But instead of being the mediator, you can end up putting the focus on yourself. You can become the message and, before you know it, people can start basing their faith on you instead of God."

Catholic priests, of course, are not alone in this temptation. There are plenty of other preachers, in this media-saturated age, who act like stand-up comedians or performers in their own faith-based reality shows. Many big churches have been known to tremble when a skilled communicator leaves the pulpit.

The Pfleger case, said Kavanaugh, is particularly sad after his decades of service at St. Sabina's on Chicago's South Side.

The sandy-haired, blue-eyed priest has helped build a thriving, predominately black parish and parochial school. Pfleger has clashed with gang leaders as well as bishops, while adopting two African-American sons and leading campaigns against alcohol, cocaine, cigarettes and other addictions. He has been hailed as a spectacular preacher, especially on the sin of racism, in an era in which Catholics are not known for their pulpit skills.

The problem is that success leads to unique temptations.

Father Pfleger and clergy who make similar mistakes are not "crazy persons. But they do have problems of their own," stressed Kavanaugh, writing in America, a Catholic weekly. "They are the problems of the preacher. ... I know there are few moments to compare with the affection and approval of parishioners after Mass, especially if you have been helpful in strengthening their faith. But the most distressing moment for me was the one homily I gave that evoked applause. Of course, it was gratifying; but it was disturbing. What was the applause for?"

It's easy for preachers to keep telling the faithful what they want to hear, he said. Preachers must be self-critical and become aware of when they avoid some tough subjects or choose to soften a message, in order not to offend. The flip side of this is when preachers decide to pound away on popular subjects and easy targets, seeking to please people who are already in the pews.

One way for priests to regain perspective, said the Jesuit, would be reading -- in the pulpit -- classic sermons by the saints or popular Christian writers that focus on timeless issues. Another way to keep from "defanging the Gospel" is to confront a congregation with the undiluted words of a sermon by Jesus, as written in scripture.

"Whether you are preaching to liberals or conservatives, it's hard to tell people truths that they don't want to hear," said Kavanaugh. "It's hard to tell people to love their enemies. It's hard to tell people to repent of their sins and to forgive others. ... If your people are smiling and applauding all of the time -- all of the time -- that's when warning flags need to go up."