~ VPN is not bad as long as it isn't specially said to be a banned offense. And I have to say, using another IP other than yours, hell using an IP that is not even from the same place as yours, would always end up blowing back on your face for sure. Doesn't mean that it will be caught right away, or even if not caught, doesn't mean it will not create a problem.
But why? Can't you be travelling, for example? These days many people travel a lot, and they have their laptop with them. If today they log in to Duelbits from Madrid, and the next day it's Berlin, they can be traveling or they using VPN, how can you tell?
But, that doesn't change the fact that we are not dealing with something special here, and that's an important difference. We should be focusing a bit more towards the fact that VPN is not illegal to use, but it is frowned upon when you do something wrong and they will always be looking to find something you did wrong.
Yes, it's their right, let them look. Only it shouldn't take long, and if you are doing nothing wrong, you should be allowed to play from wherever you want.