Not accepted?  You mean as legal tender?  Bitcoin is accepted in most countries around the world.  Only few decided to crack down on it and imposed a ban.

It can not be controlled as in the Government can not impose a reorganization of Blocks, an Address to be emptied out into the Address of Authorities et cetera.  They can however seize paper containing your Seed or break in to your Computer to access your Coins of course.

But you can get a virus and have your Coins stolen.  The Bitcoin Blockchain can not be hacked, but you and your Wallet can be.  This means you still need to give Security a lot of attention to ensure you will not be a victim of a sad story.

Good luck.