A former music teacher who persuaded girls to perform sex acts over the internet has been jailed for two years and eight months.
Graham Conridge kept records of the girls he contacted
Luton Crown Court heard Graham Conridge, 59, admitted posing as a teenage boy to contact 261 girls aged 11 to 15 through MSN and chatrooms.
He kept records of what the girls were prepared to do, the court heard.
Conridge, of Byron Crescent, Bedford, was also found with more than 16,000 indecent images of children
Prosecutor Natalie Carter said although Conridge had told the girls he would like to meet them, no active arrangements were ever made.
When they examined his computers police found 16,183 images and videos of child sex abuse.
Explicit text messages to girls were found on his mobile phone.
Conridge was caught when the Serious Organised Crime Agency's Child Exploitation Online Project took control of a chat room being used by paedophiles.
Conridge pleaded guilty to 17 charges of making indecent photographs of children and seven charges of inciting a child to engage in sexual activity.
Defence barrister Katherine Davey said Conridge was of previous good character and had expressed remorse.
Judge Michael Kay said: "This was a shocking case. It is a warning to all parents of teenage children of the dangers of allowing them unsupervised access to chatrooms."
He said the young girls had felt humiliation and strong feelings of revulsion after discovering who had been watching them.
Conridge was banned from working in schools five years ago after allegations were made of inappropriate behaviour.
In a statement Bedfordshire County Council, which had employed Conridge, said: "Five years ago Graham Conridge was banned from working in any of the county council's schools following serious allegations of misconduct.
"We decided that the nature of the allegations made against Mr Conridge meant that we should take this action, which was the strongest available to us.
"The subsequent sentencing of Mr Conridge for a number of offences justifies the prompt action we took."