From my Quora answer:

The way this question is phrased is problematic.

Are pencils useful to criminals? They can be used to write down schemes for robbing banks, kidnapping letters, etc.

What about guns? Weapons give criminals an edge in committing crimes.

Of course, pencils and guns can be used against criminals as well. Most people would agree that it’s a good idea that weapons exist (even if you think that only the policy and military should have them) — otherwise, the strongest bullies could force their will on everyone else, and society would collapse.

So what you should really ask is – will Bitcoin lead to more crime or less?

Arguments for more crime:

* The quasi-anonymous nature of Bitcoin makes it very convenient for extortion payments, bribes, etc.

* Stealing Bitcoin can be easier than stealing cash given that it is portable, easy to transfer, the transactions are irreversible, etc.

Arguments for less crime:

Governments steal far more than common criminals by inflating the money supply and collecting taxes. Bitcoin makes it impossible to steal by inflating the money supply (of Bitcoin) and makes it harder to collect exorbitant taxes.

For example, read:

Why are Venezuelans mining so much bitcoin?
Inflation at 8900% Turns Venezuelans to Bitcoin In Record Volumes

* If Bitcoin is properly secured (on hardware wallets, in a vault, in your head), it can be harder to steal. Again, most theft is committed by governments, especially in the developing world, and cash is a lot easier to find that properly protected cryptocurrency.