MADISON, Wis. (AP) -- The state's Revenue Department says it has sent out more than 1,000 letters this year to smokers who bought cigarettes online.

The letters tell them to stop buying cigarettes that way or to pay the $1.77 tax that's now in effect.

The letters could mean the smokers could be billed if their names show up as repeat buyers.

The state got the names from Internet cigarette vendors after notifying 75 of them that a federal law makes it their responsibility to ensure Wisconsin gets the tax money.

Officials have refused to say exactly how many smokers got the letters or how much in taxes they've collected from the efforts.

State Revenue Secretary Roger Ervin says they're not saying much about how they got the names of the customers so they don't jeopardize relationships with Internet vendors.