The U.S. government has worked hard over the past decade to stop Americans from hiding bank accounts offshore to evade taxes.

But not hard enough. It has become more difficult to maintain secret accounts, but it’s still happening, as recent examples show.

People who have dual citizenship, minimal connections to the U.S. and a willing accomplice at a bank have the easiest time. But even those who are solely American citizens can get away with offshore accounts by using complicated trusts or soliciting family members overseas. Having an account offshore isn’t illegal, but not disclosing it to the Internal Revenue Service is.