Denmark is trying to remove cash from the monetary system (article). There are many reasons (excuses) to drive on this direction: less cost, anti money laundering, fight against terrorism... However we think what is behind this trend is purely power hunger and control of the population. Cash is one of the few things that is almost private (almost because sometimes the numeration of the bills is tracked). Privacy and freedom are values that shouldn't be compromised for any reason. And of course, the bad guys will have means to get away with the regulation with no problem.
But you might think it is just one country. No. It's a global trend. France receintly reduced the maximum amount of cash for transactions to only 1000 euros. If you haven't watched it, please check out Citizenfour, either the movie or the book, to see until which point we are under undiscriminated surveillance.
Just as a reminder we leave this link here about the movement of cash in and out of European Union. Be careful, it might change at any moment.