Analysts say about US$1.2 billion in cryptocurrency has been stolen since the beginning of 2017.

“One problem that we're seeing in addition to the criminal activity like drug trafficking and money laundering using crypto-currencies is the theft of these tokens by bad guys,” Dave Jevans, CEO of cryptocurrency security firm CipherTrace, told Reuters.

Mr Jevans also chairs the Anti-Phishing Working Group (APWG).

He says the European Union's new General Data Protection Regulation will actually make things worse.

“GDPR will negatively impact the overall security of the internet and will also inadvertently aid cybercriminals,” Mr Jevans said.

“By restricting access to critical information, the new law will significantly hinder investigations into cybercrime, cryptocurrency theft, phishing, ransomware, malware, fraud and crypto-jacking,” he added.

“So what we're going to see is that not only the European market goes dark for all of us; so all the bad guys will flow to Europe because you can actually access the world from Europe and there's no way you can get the data anymore.”