Efforts to make the net less risky for children are being marked by the fourth Internet Safety Day on 6 February.
Events are being held in 31 nations and a blogathon will record activities held as far apart as Australia and Canada.
One UK event sees the launch of a training scheme to give those working with children experience of the risks associated with net use.
The day falls as US research suggests many teenagers often stumble across pornography online.
The day, intended to raise awareness among parents and teachers as well as youngsters, has been organised by the EU's Information Society and Media Commissioner Viviane Reding.
"I am calling upon all decision-makers in the private and in the public sector to help make the internet a safer place for the most vulnerable of our society," she said.
As part of the day, 20 of Europe's leading mobile operators - including Vodafone, Orange, Telecom Italia and Deutsche Telekom - have signed an agreement intended to offer greater protection for youngsters using mobile phones.
YOUNGSTERS AND MOBILES
In the UK 14% of children have been victims of bullying by mobile
In Germany, 92% of 12-19 year-olds had a mobile phone in 2005
In Italy 31% of 5-13 year-olds have mobile phones and nearly 100% of 14-18 year-olds
In Lithuania, Latvia and Greece more children own mobile phones than have net access
The self-regulatory codes, which will come into force in February next year, include controlling access to adult content, awareness-raising campaigns for parents and children and the classification of commercial content according to national standards of decency and appropriateness.
The blogathon is intended to showcase the materials produced by hundreds of schools around the world dealing with the risks and rewards of net use. Over the past few months schools have been collaborating to make net safety information dealing with images, privacy and online etiquette.
One of the events in the UK is a conference that aims to promote safe and responsible use of the net among young people.
The Cyberspace Research Unit (CRU) at the University of Central Lancashire is the UK co-ordinator for Internet Safety Day and is using the day to launch a training scheme for those who work with children that use the net.
Dr Denise Carter, a research fellow at the CRU, said the course was designed to close the digital divide separating young and old.
Carter: It's about ways to help kids deal with the bad experiences
"There's a huge gap between what the children use technology for and what older people do with it," she said.
"Older people use it as a tool but for younger people it is a way of life," she said.
The training scheme aims to bridge this gap by giving those working with children experience of the many online communities and familiarise them with the pitfalls and risks they offer.
"It's about ways to help kids deal with the bad experiences," said Dr Carter. "Children need people that understand what these risks are and who they can report them to."
Dr Carter said the course aims to help teachers spot the early signs of trouble such as when children are being targeted by potential abusers or their peers are subjecting them to cyber-bullying.
The course also deals with training and teaching techniques that help children use the net more responsibly. "It's about changing their behaviour and getting them to stop and think," said Dr Carter.
The scheme is being launched as research in the journal Pediatrics reports that 42% of young people aged 10-17 questioned for the study had seen sexually explicit material online.
Two-thirds of those who reported seeing this material said their viewing of it was accidental. Much of the accidental viewing came as a result of using file-sharing software to download images.
"Although there is evidence that most youth are not particularly upset when they encounter unwanted pornography on the internet [it] could have a greater impact on some youth than voluntary encounters with pornography," said the study.
In the UK, British Home Secretary John Reid has said he is considering making paedophiles add their chatroom names to their other details on the Sex Offenders Register.
And sex offenders could be forced to register their e-mail addresses to prevent them approaching children on the internet, the UK government has said.