Mike Klemens of the Illinois Department of Revenue says Internet retailers are required by law to give states a list of their customers.
Illinois then periodically bills Illinois taxpayers who bought online and didn't pay the state cigarette tax which is currently 98 cents a pack.
Since the Revenue Department began such efforts in 1999, it's billed more than 4,600 taxpayers about $232,000.
Klemens says billing people is a lot of work, so the department doesn't do it often, but he says he expects the Revenue Department will step up its efforts if Gov. Rod Blagojevich's proposal to increase the cigarette tax by 75 cents a pack is passed.