By Shane Harrison Dublin correspondent, BBC Northern Ireland

The couple who are the driving force behind Bebo, the website that is partly aimed at young people, have been to Dublin to respond to criticisms that the site is being used for pornographic and sectarian purposes.

Material on the Bebo site has been used to bully teachers

This follows a BBC Newsline investigation in which reporters were able to use fake identities to access material.

Sitting in their suite in Dublin's upmarket Westbury Hotel, just off the pedestrian and chic Grafton Street, Michael and Xochi Birch look like a typical dot com-type couple.

He's an Englishman with long hair and a T-shirt and she's a native of San Francisco, the city most associated with Silicon Valley.

In January 2005, they founded Bebo which they describe as "the next generation social networking site where members can stay in touch with their college friends, connect with friends, share photos, discover new interests and just hang out".

The site, which gives young people their own webspace, has become a huge hit with students in Ireland, in particular with children as young as 13 regularly visiting it.

But concerns have been raised in Northern Ireland by school principals and children's charities that some people have been using fake identities to put pornography and sectarian literature on the site.

'Privacy and safety'

There is also evidence that material posted on Bebo has been used to bully and harass both other students and occasionally teachers.

Michael Birch says Bebo takes privacy and safety "very seriously".

"We have a dedicated customer service centre, which we recently opened in Austin, Texas," he said.

"We have 20 full-time people who respond to reports of abuse.

"We have safety tips on the website, we employ Dr H O'Connell, who is our chief safety officer and we're working on a lot of initiatives to make Bebo as safe as it can be."

I showed Michael some of the material, including gay pornography, BBC Newsline had found recently on Bebo school sites.

Fake identity

He said: "Whenever I do find inappropriate content on Bebo, I look at how long it's been there and I generally find it's been there for less than 24 hours."

He accepts that Bebo can't prevent people creating fake identity accounts but his company "can respond as quickly as possible and take the appropriate action".

On sectarianism, he says that while Bebo is in favour of political expression, it is totally opposed to hate crime.

It also takes a strong line on "pornography and cyber-bullying".

But Michael Birch also says parents must accept that the internet is not going to go away and is here to stay, so they, too, must accept a role in policing what their children get up to.

"It's important that parents actually understand what Bebo is, how to use it and they can work with their children and discuss it with their children.

"It's basically common sense," he said.

Bebo's message appears to be that while the company will do all in its power to prevent a tiny minority from causing offence, it can't guarantee total success all the time and everyone has a role to play in preventing children from accessing unwanted sectarianism, cyber-bullying and pornography.