"They are savvy with social media and are always connected, sharing more online information than any other age group.
"However, millennials are also the generation most willing to gamble their privacy and security in exchange for a life online."
His company's survey found 12 per cent in the younger group admitting to sharing online virtually everything in their daily lives. That compared with just 1 per cent of people aged over 55.
But although 59 per cent of millennials acknowledged using social media sites with low privacy settings, the company says its survey proved that life online had "real-world" consequences.
That dose of reality often came from the workplace, as 12 per cent of the younger group admitted receiving warnings from their employers about content they had posted on the internet.
Mr Gorrie said "an alarming" 31 per cent believed they needed a break from social media.
Neither had there been any let-up in an increase in cybercrime, as indicated by 65 per cent of younger respondents admitting being stung by computer viruses, 27 per cent by phishing scams, 8 per cent by online identity theft and 5 per cent by ransom-ware attacks.
Even so, 54 per cent claimed they could not last more than a day without checking their online social networks, compared with 34 per cent of participants aged over 55.
The company - a leading supplier of computer security software and patches - found that 71 per cent of younger participants left their digital devices unprotected, compared with 51 per cent of the over-55 group.
Mr Gorrie said millennials were the first generation born into an online world, which they had turned into "a fantastic platform to learn, connect and interact with friends and family across geographies".
But he said the survey provided a cautionary tale.
"Millennials need to be wary of the content they share, tweet, post and upload ... This includes turning off location settings on certain applications ..."
Top police tips
• Don't post your address, phone number or other personal information you don't want everyone to know
• Read through privacy options carefully and make sure you thoroughly understand your rights
• Set your profile to "private" so only the people you want to see it can do so.
• Send "friend" invitations to or accept offers from only people you know.