Pope Francis has warned of the dangers of allowing children to have computers in their bedrooms, saying it can lead to them watching pornography.
The Pope spoke in approving terms of "parents who don't allow computers in their children's bedrooms, but put them in a communal room in the house. These are small things that parents can do to avoid (the problem)."
Many parents were "very worried" about the risks of their children accessing websites containing sexually explicit or violent material, he said.
"There are dirty things, from pornography to semi-pornography, to programmes that are empty and without values - for example, programmes that are hedonistic and consumerist. We know that consumerism is a cancer in society."
The Argentinean pontiff said children were becoming far "too attached" to digital media such as computers, tablets and mobile phones.
"It harms the soul and curtails freedom - it makes you a slave of the computer," he said.
He said that while it was important for younger generations to master digital technology, computers and other devices should be used with moderation. He said parents who allowed their children to play with smart phones during meal times often complained that their offspring were in "a different world".
He made the comments on the official papal plane on his return from a one-day visit to Sarajevo at the weekend, but they were not reported and only came to light yesterday. Last month, Pope Francis revealed that he had not watched television for 25 years - not even the matches played by his beloved Buenos Aires football team.
In an interview with an Argentinean newspaper, he said he last switched on a TV in 1990.
After that he simply decided that "it was not for me", he told 'La Voz del Pueblo'.
To find out whether his team, San Lorenzo, wins or loses, he has to ask members of the Swiss Guard, his personal protection force, who draw up a table of results for him each week.
Having called for "a poor Church for the poor" when he was elected by his fellow cardinals two years ago, the Pope unveiled his latest gesture for the marginalised of society - a homeless hostel in Rome.
The 30-bed dormitory will be established in a building just a few hundred yards from St Peter's Basilica.
The hostel is expected to be opened in the next few weeks.
In his two-year papacy, the Pope has shown keen interest in the plight of Rome's homeless, giving them sleeping bags during the winter, inviting them on an exclusive tour of the Sistine Chapel and, last week, having them taken by bus to Turin to see the Turin Shroud, the supposed burial cloth of Christ.