UK Prime Minister Theresa May has promised to consider clamping down on bitcoin as she raised concerns that cryptocurrencies are being used by criminals.

“In areas like cryptocurrencies, like Bitcoin, we should be looking at these very seriously,” May said in a television interview in Davos with Bloomberg’s Editor-in-Chief John Micklethwait. Action on crypto-currencies may be needed “precisely because of the way they are used, particularly by criminals,” she said.

The digital currency can be used to buy anything from drugs to cupcakes and is seen as having the potential to reshape the global financial system. The price of bitcoin soared in 2017 but there have been calls for cryptocurrencies to face tougher regulation.

The surge in bitcoin use has been “increasingly developing,” May said on Thursday. “I think it’s something that we do need to look at.”

When the UK leaves the EU, May wants more technology companies to set up in the UK Britain “already has a leading edge” in the development of artificial intelligence, she said. “We are already an attractive place for businesses to come and set up.”