Imagine waking up one morning and finding all your bank accounts have been cleaned out. The IRS will take every dime. If this amount did not cover what is owed, the IRS keep taking your money until you cover your income tax liability. The IRS is fully aware that levying your bank account will cause checks to bounce, alerting many people that you have tax problems. But they don't care! Their sole objective is to collect the income taxes owed. Period.
As bad as that is, a worse method is a wage levy (or garnishment). That's when most of your paycheck goes to the IRS. The IRS will leave you not enough money to pay your bills, and most of your check goes to the IRS each and every week until your income tax debt is paid.
If that doesn't accomplish what they want, the IRS will pull out all the stops. The IRS will seize your assets, and sell them at auction. That includes everything you own; home, cars, boats, jewelry, motorcycles, insurance polices, retirement funds, anything of value.