As far as my limited knowledge on crypto is, majority of blockchain tech wallet content is public. For example, BTC and ETH both have blockchain explorers that you can view balance in any address. Only XMR is the only that wouldn't allow an explorer.

Tricky thing is that Steemit links your identity to your wallet and it makes it easier for people to see. However, even if you manage to hide it, there is still ways to find out how much you have. SteemD and SteemDB would show most of the infos anyway.

I want a hardware wallet for Steem, too, like a USB stick or something. That'd be nice.