Pope Benedict XVI (search) said Sunday that the media can spread peace but also foment violence, and called for journalists to exercise responsibility to ensure objective reports that respect human dignity and the common good.

Benedict made the comments during a brief appearance at his studio window to bless the thousands of people in St. Peter's Square (search) below, following in the beloved Sunday tradition of Pope John Paul II (search).

Noting that Sunday was the world day of social communications, the pope praised the media for what he called the "extraordinary" coverage of the death and funeral of John Paul. "But everything depends on the way it (the media) is used," he said.

"These important tools of communication can favor reciprocal knowledge and dialogue, or on the contrary, they can fuel prejudice and disdain between individuals and peoples; they can contribute to spreading peace or fomenting violence."

As a result, Benedict called for members of the media to exercise "personal responsibility" to ensure objective reports that respect human dignity and pay attention to the common good.

The call was similar to one Benedict issued April 23 during a meeting with journalists in his first public audience after being elected pope April 19. Then, he reminded members of the media of their "ethical responsibilities" and urged them to seek the truth and safeguard the dignity of the human person.

John Paul made similar calls during his nearly 27-year pontificate.

Earlier Sunday, Benedict appeared by surprise at his studio window to greet children and wish mothers in the crowd a Happy Mother's Day, Italian news agencies reported.

In his second Sunday greeting from the Apostolic Palace, Benedict blessed pilgrims and tourists in Italian, English and Spanish, and was interrupted a few times by applause — particularly when he mentioned John Paul.

His appearance came a day after he participated in the final ceremony of his formal assumption of the papacy: a Mass at St. John Lateran, Rome's cathedral and Benedict's seat as bishop of Rome.

During his homily, Benedict pledged to resist attempts to water down Vatican teaching, indicating he would uphold John Paul's unwavering stands against abortion and euthanasia. The pope "must not proclaim his own ideas, but ever link himself and the Church to obedience to the word of God, when faced with all attempts of adaptation or of watering down, as with all opportunism," Benedict said.

"That's what Pope John Paul II did, when ... faced with erroneous interpretations of freedom, underlined in an unequivocal way, the inviolability of human beings, the inviolability of human life from conception to natural death," Benedict said.

"Freedom to kill is not a true freedom but a tyranny that reduces the human being into slavery," the pontiff said, to ringing applause from the congregation. In Vatican teaching, references to defense of life "from conception to natural death" refer to its bans on abortion and euthanasia.

Benedict, the former Cardinal Joseph Ratzinger, was John Paul's chief theological adviser on such issues in his 24 years as prefect of the powerful Congregation for the Doctrine of the Faith.