So..a state AND a federal agency use the same phone number???

A civil dispute about tax liability is NOT tax evasion.  Tax evasion is a crime.  These companies DO in fact search public records for tax liens and then offer their services to the parties listed on the documents.

A filed tax lien is not evidence of tax evasion.  It does indicate that the parties could not reach an agreement as to tax liability.

Doesn't mean that the taxpayer is engaging in tax evasion.