David Clark from the Economic Crime Directorate said that while JT and Sure's investments would create a huge amount of opportunity it would also have a downside.
'For me, Guernsey is going to thrive on the opportunities of this faster internet, but while it is thriving and not looking back, then there is always the potential to get caught out by fraudsters,' he told guests at the 5th AO Hall biennial fraud conference, Catch Me If You Can, yesterday.
'Crime rates are really low and that often makes you more vulnerable and because your guard is slightly lower. It's the "hasn't happened to me" syndrome.
'You are at risk and you do need to put your defences up and you need to collaborate.'
Cases of online crime in the UK have risen from 20% to 30% two years ago to 70% last year, he said. Fraud is also estimated to cost the UK economy £52bn. a year.
Supt Clark also talked about the different types of fraud, including cyber crime, boiler rooms and online shopping, auction and ticketing fraud.
He felt prevention was key to winning the fight against it.