Facebook has said it will block any advertising promoting crypto-currency products and services.
The company said it was open to emerging technologies but many companies were not acting in "good faith" when extolling the virtues buying into virtual currencies.
Recently, a wave of new currencies have emerged, seeking to piggyback Bitcoin's huge increase in value.
Facebook urged users to report any ads the company's security measures missed.
It admitted it would not always catch every ad for a crypto-currency.
“We want people to continue to discover and learn about new products and services through Facebook ads without fear of scams or deception," wrote Rob Leathern, product management director for Facebook Business.
"That said, there are many companies who are advertising binary options, ICOs and crypto-currencies that are not currently operating in good faith.”