Can anyone help? I received a letter from the IRS that coinbase, in 2018, reported over a million dollars worth of transaction on a 1099k of which I know nothing about. The IRS claims that I owe 305,000 in taxes. I disputed it and sent emails to coinbase with no luck, they don't return my emails. I have a coinbase account and downloaded all the transactions I ever made but other than that I'm freaking out about what to do. Anyone ever heard of this happening or have any suggestions as what I should do?