A cheer spread around the internet in March when the EU voted against proposals that could have led to internet service providers (ISPs) having to 'police porn' online. If this felt familiar, it may be because MPs here rejected similar proposals in December that would have forced ISPs to block porn unless computer owners requested otherwise. Although temporarily shot down, campaigns to filter porn from young people's lives that drove these proposals haven't disappeared.

A similar Online Safety Bill remains in discussion in the House of Lords, and with online porn block advocate MP Claire Perry now the PM's adviser on childhood sexualisation, the government has reasserted its support for preventing young people from viewing porn. With much discussion about the 'damage' online porn does to young people, it's important to reflect on what we actually know.

These campaigns are often based on assumptions that excessive exposure to online pornography is harmful to young people. In truth, partly due to ethical challenges of discussing sexual topics with young teenagers, we know little about the impact pornography has on their sexual behaviour. A 2010 Ofcom peer-reviewed report of available studies found they showed no conclusive evidence that sexually explicit material 'impairs on the development of minors'.

Dr Clare Bale is a management consultant and sexual health expert whose research looked into how young people engage with sexual media. She believes they have more control than they're given credit for.

"Often you hear that young people are 'exposed' to pornography but what I found is that they engage with porn in a number of ways," says Bale. "They share porn for the 'yuck' factor, the humour factor and for pleasure. Some look for pornography but if a pop up appears online and they don't want to engage then they shut it down."

Although many professionals share Bale's view, this nuanced understanding of how teenagers engage with pornography doesn't tend to make headlines. The shock tactics that do, highlighting isolated incidences of sexual violence as proof of the corruption of young people by porn, can cause problems.

"If we moralise about it then we're closing down spaces where young people can legitimately talk about sex and sexuality," says Bale.

Sexual cultures academic at University of Sunderland, Dr Clarissa Smith, points out that trying to block porn is not a neutral act.

"By blocking things you're saying this is so bad you shouldn't see it. At some level, we're saying the human body is something that ought not to be looked at," says Smith. In research carried out by UK Safer Internet Centre last year, 13 to 14-year-olds reported that the fear of being judged prevented them from talking to an adult. Initial responses to an online survey into teenage pornography use by Smith also suggest young people don't want their parents to feel ashamed. Encouraging the message that porn shouldn't be looked at risks strengthening this barrier and efforts to try to block online porn distract from what young people actually need.

"None of those campaigns are very interested in thinking about how you might equip kids with the skills to understand the images they are seeing or to deal with how they feel about sexuality," says Smith.

Education specialists working with young people are quick to criticise suggestions that teenagers are spending all their time alone in their room masturbating furiously to online porn. Justin Hancock is an author of a book about sex and relationships for young people, whose website BishUK and resources about porn are widely used.

"I think it's often exaggerated how much young people are actually looking at porn on the internet," says Hancock, who sees teenagers more interested in gaming and social networking than pornography. For the occasions it is watched, he believes teenagers need safe spaces to ask questions and get clarification.

"Young people I work with know that porn isn't real life but sometimes they need to know which parts aren't real," says Hancock. "It's about filling in the gaps where traditional sex education ends and porn begins. I try to give young people the tools to be critical and literate consumers, which they are."

With sexual images in adverts, TV, newspapers and magazines as well as online, these critical skills have broad uses. Looking at wider sexual media with teenagers is something sex and relationships educator Gareth Cheesman finds useful. Cheesman asks teenagers to think about how sex and body images are presented on TV and in films, and then encourages them to take the same approach with pornography.

"Hopefully this builds in the skills and attitudes to be more critical in the future," says Cheesman. "Young people don't need to be lectured but encouraged to develop critical skills to protect their future expectations about what makes a happy, healthy sexual relationship."