Open Rights Group and LSE Media Policy Project launched a new report, 'Mobile Internet censorship: what's happening and what we can do about it'  on Monday 14th May.
The report reveals widespread over-blocking, showing that political commentaries, personal blogs, restaurants' sites and community websites have been blocked incorrectly on mobile networks' child protection filters.
It calls on mobile operators to give parents an 'active choice' to turn filters on, and to be far more transparent about how their systems work.
The report also argues that applying similar blocks to fixed-line broadband, something advocated by Claire Perry MP, will have the same damaging consequences.
Peter Bradwell of Open Rights Group and author of the report, said:
"This report shows how child protection filters can actually affect many more users than intended and block many more sites than they should. These blunt blocks effectively add up to a system of censorship across UK networks.
The lessons for 'porn filter' proposals are clear. Default-on blocks can have significant harmful and unintended consequences for everybody’s access to information.
To help protect children online, the Government should reject 'default on' network filtering and work to give parents simpler choices and better, device-based tools."
For more information contact Peter Bradwell on 07811 268398 or firstname.lastname@example.org
 Responses from Index on Censorship, NSPCC, the Mobile Broadband Group, the think-tank Demos and others will be published by LSE Media Policy Project through the week.