A study commissioned in the UK by Ofcom found almost half of those questioned (46%) said they had been personally drawn in by an online scam, while two in five (39%) knew someone else who had fallen victim.
A quarter of those who encountered online fraud had lost money as a result, with a fifth (21%) being scammed out of $1,000 or more.
However, 2 in 5 people took no action, mostly believing it would not make a difference.
More than a third of all victims said the experience had an immediate negative impact on their mental health, increasing to nearly two thirds among those who had lost money.
Men, younger adults aged 18 to 34 and those with children in the household are significantly more likely to have seen suspected scams.
Among those who had experienced online scam or fraud, almost a quarter (23%) first encountered it on social media.
Impersonation fraud was the most common type experienced at 51%, followed by counterfeit goods scams found on online marketplaces.
Potential victims were most commonly contacted via a direct message or a mass message posted to a social media group, 20% were reached through online ads while others were targeted through “user-generated” and influencer posts or videos.
Ofcom’s director of online safety policy, Richard Wronka, said: “Falling victim to online fraud can have a devastating impact on people’s financial and mental wellbeing.
“The UK Online Safety Bill will place new obligations on online services to protect their users against online fraud and scams.
“Today’s report provides crucial evidence that will help to inform our approach to implementing those new laws when they arrive.”
Ref: Yonder on behalf of Ofcom surveyed 2,097 UK adults over a 14 day period online last year.