Would have to be careful with it, or stop using it. But if i had a lot of bitcoin i would just move to a better country that didn't ban it.
Me either I will become cautious and careful if the government will declare bitcoin as illegal in our society. But I will still keep on using it because there are a lot of ways that I can still consider to keep on using bitcoins with the help of mixers and as well as some exchange sites. But it looks like that I am already a criminal if I did that.