...on a screenreader. Moonan says that many disabled users have to rely on friends and family to complete Captcha forms on their behalf, and those without anyone to help them are often locked out of the networks altogether. "There are alternatives on some of the sites, but even they are very problematic," says Moonan. "It's a massive issue."
Of all the major networking sites, the most problematic for disabled users is probably MySpace. It relies heavily on tables and users of screenreaders aren't able to read pages if the user has added music. "One of the biggest issues is that the sites aren't suitable for people who use screenreaders, including people with visual impairment or dyslexia," Carter says.
In general, social-networking sites have not been designed with the needs of people who use assistive technologies in mind. This can make it difficult for individuals who have paralysis or other physical disabilities, says Alex Rankin, a spokesman for Aspire, a charity that works with people who have suffered spinal injury. "Lots of our clients use voice-recognition software from Dragon, which works brilliantly in Word, but less well in a web environment," says Rankin. "I had one person tell me that they had to stop writing messages in Facebook, because every time he said the word 'back', the site would take him back to his profile page."
Other disabled users may rely on devices such as a Tracker Pro, which uses a camera on the computer, and a reflective dot worn on the user's clothing to direct the computer cursor. "Essentially, it lets you move the cursor left by turning to the left," explains Rankin. For this kind of technology to be useful, websites need to have large buttons and icons.
Similarly, users with no movement in their limbs, or poor dexterity may rely on an Integra Mouse, which can be controlled using the lips and mouth. "It looks like a joystick, but you use the tongue to control the movement," explains Rankin. "To left-click the mouse, you suck; to right-click, you blow."
Most mainstream social networks don't offer a simplified audio or "text only" version of their pages, which can cause problems for disabled users such as Dean Meuleman, who works with Mencap as a communications assistant, and also has a learning disability. "I use Facebook and I think it's a good way of getting in touch with people you haven't spoken to for a long time. Some people find it easier to say things in writing rather than face to face," he says. "But it can be hard to use and confusing when people send you stuff, and I can only do the basic things."
Common features of social networking, such as friend invitations and privacy settings, can seem very complicated to people with learning disabilities, and Meuleman says he also finds the search function tricky to use — he would prefer a simplified search function with keywords that would make it easier to find people. "At the moment, I can't look for friends because there are lots of people with the same name, and it stops people searching as it takes too long."
Meuleman would like to see more people with learning disabilities on Facebook — at the moment, he knows only a few colleagues and one friend from outside work who use the site. "I think if you want more people with disabilities to use Facebook, you should have a support service that will help people and encourage them to use it," he says.
Social networks can also present threats to vulnerable people with disabilities, according to Caroline Lambie
Mencap web communications manager. "People with autism and aspergers might be good computer users, but they're very vulnerable online because they're not aware of social behaviour," she says. "Sites need to tighten up the privacy and control settings and make them easier for people to understand."
Lambie would also like to see safe, moderated environments within social networks that provide audio, video and clear text versions of the features that other users take for granted. "People tend to think of accessibility as being just about blind users, but there are lots of other disabilities, and those ought to be catered for just as much," she says.
A lack of accessibility is driving many disabled web users to create their own, alternative social-networking platforms. US-based sites such as Disaboom and Don't Dis Me, for example, provide disabled people with a secure, accessible online community along with advice, forums and information. In the UK, there are a growing number of social-networking sites for disabled people, including Y-A-P, launched earlier this year by Mencap, and CKfriends.org.uk, a Scottish site that provides a safe online community for adults with learning disabilities.