The problem with oppressive governments (are there any another kind?) is that they can and will use a transparent blockchain to attack their enemies.

To them an enemy is anyone who threatens their positions of power. They can instruct the exchanges to not accept transactions from certain accounts or as you pointed out use brute force to compel you to give up your account.

It seems to me that a transparent blockchain will empower governments to go after anyone that opposes them.

So the question is...who is willing to be the a martyr?