Although tax avoidance is completely legal, it is dangerous. You can freely do that but you have to make sure that you're a friend with the government. If not, there's always a reason for them to give you headache. There's always something for which you'd be held accountable.
Roger Ver did tax evasion, not tax avoidance.
He didn't report all of the true capital gains he made. If he did tax avoidance, he need to report all the gains to IRS, but he could make a fake story by saying it's a charity money for non-profit business or other thing that didn't get/very low tax.
Many rich people try to evade as much tax as they can it’s honestly crazy especially thinking just how much money they have.
This is not happen on rich people only, but it happens here too!
Someone who live in third world country and get paid enough here need to report their earnings.