Is this possible? Hard? Easy?

I am not so sure that privacy at the protocol level will ultimately be good for BTC on account of the need for auditability of governments and other criminals. However, that might be outweighed by the need to protect people and honest companies from those very governments. Come to think of it, governments probably have plenty of ways of sidestepping audits even with everything in plain view. Yeah this really ought to happen.

If you want to be well known - there is no privacy ..

If you stay unknown - you don't need privacy ..

In between - yes ! But they should be able to figure out add on tools .. #bitcoin is a public ledger ..