Indirect auditing

[Marcia]

I am writing a paper on inappropriate or unusual/non-traditional methods revenue depts or audit depts have used to detect non-compliance to state and local tax, primarily sales and use tax. i.e. obtaining online customer lists from internet vendors. Please submit examples you are aware of. Thanks.

[Mr. Knowitall]

Driving by a taxpayer's business or place of residence, to see if their obvious expenditures are in line with their claimed revenues.