When using TurboTax Online, I would always recommend that you download a copy of your tax return to your own computer—both the data file and the PDF of “all forms and worksheets”. However, there is no way to remove the online copy from the cloud. I believe IRS regulations require it be kept for you. If you set a unique password (that is not reused on any other web site) and you turn on 2-factor authentication with your cell phone or email address, it should be well secured.