We can fill in that "...." with whatever we want of course. For Bitcoin enables (despite whatever other fragilities we might think it has) people to transfer money around, do business, trade, without the intervening hand of the State. And that will never do: how can the functionaries of the State make sure they get paid if we just do things without paying them their tithe in tax? And thus:

European Union countries plan a crackdown on virtual currencies and anonymous payments made online and via pre-paid cards in a bid to tackle terrorism financing after the Paris attacks, a draft document seen by Reuters said.

In more detail:

They will urge the European Commission, the EU executive arm, to propose measures to "strengthen controls of non-banking payment methods such as electronic/anonymous payments and virtual currencies and transfers of gold, precious metals, by pre-paid cards," draft conclusions of the meeting said.

The bodies are not even buried yet, we know absolutely nothing at all about how this attack was financed. And yet everyone knows that cyber-currencies must be more regulated. Because......

Well, just because, because we cannot be allowed to do things beyond the purview of the State and any old excuse is a good enough because to make sure that that is not allowed to happen. The terrorists could have been using their own bank accounts and we'd still be having this clampdown. Because.