Wall Street’s main regulator has repeatedly warned that the hot new market for initial coin offerings is probably full of fraud. Now it’s found an old-fashioned way to slow it down: picking up the telephone.

More than a dozen crypto-linked companies have shelved plans to raise money from investors after Securities and Exchange Commission officials called them up, Robert Cohen, head of the SEC’s cyber enforcement unit, said Friday. The SEC scrutiny prompted firms to realize their offerings may have violated federal securities laws, he said at a conference in Washington.

Regulators have been sounding the alarm about ICOs since last year, with SEC Chairman Jay Clayton cautioning that crooks could be harnessing the latest technology craze to pull off a scam that’s as old as markets themselves: talking up an asset and then selling once the dumb money pours in.

Billions Raised

In the offerings, a company sells digital tokens that can eventually be redeemed for goods and services. The coins can be traded in a secondary market -- which the SEC says make them securities and subject to its oversight. As a result, SEC officials say many ICOs should be registered with the agency.

Despite the agency’s warnings, ICOs continue to attract a ton of money. They have raised an estimated $1.2 billion this year, after drawing $3.7 billion in 2017.

“It’s Wolf of Wall Street on steroids,” former SEC Commissioner Dan Gallagher, who was speaking on the same panel as Cohen, said about the amount of misconduct tied to ICOs.