Operation Bamboo officers were investigating chat-room conversations a 13-year-old girl from Stoke was having with a number of adult males.
When they raided Barnes's home, they recovered computers containing 39 indecent images and movies of children - some in the most serious category.
Barnes, of Darlington, admitted 17 specimen charges of making indecent images and one of inciting a child to engage in sexual activity.
The 24-year-old was given a four-month prison sentence, suspended for two years, with supervision and 300 hours of unpaid work for the community.
He was also told by the judge that a sex offender treatment programme he was placed upon was not available to him behind bars.
'Many people must be puzzled to say the very least at the leniency of the guideline sentencing,' the judge said. If I sent you to prison it would be for a matter of a few weeks only, hence, as I say, the puzzlement that many people would have about that.
Teesside Crown Court heard how Barnes was arrested at his family home in October 2009 following an operation carried out by Staffordshire Police.Judge Fox admitted people would be 'puzzled to say the least' at his decision.