Can the IRS Levy My Social Security Benefits, Because of Unfiled Taxes?

Yes. however, I am not sure how often the IRS uses this Notice

There is a CP 91 Notice, which is used to notify someone that the IRS is going to levy their Social Security Benefits.

The notice states that there is a balance due and is still unpaid. (Even if you didn't file, the IRS will prepare a Substitute Return, and file for you)

The notice goes on to say that the IRS intends to take up to 15% of your Social Security Benefits, and explains what steps the taxpayer needs to take, to prevent the collection actions.

For clarification on Tax Codes, visit irs.gov