It’s that time of year when candidates for political office come knocking. In Illinois, people running for everything from village board to Congress need hundreds of signatures by Dec. 5 to get on the ballot.

But the old-fashioned practice of going door-to-door is getting an update in the Internet age. Technology is allowing candidates with so-called smart phones to get up-to-the-minute information about voters before knocking on their doors.

On a recent Tuesday, the McGill household of Chicago’s Northwest Side had no idea they were strategically chosen for a personal visit. State representative candidate Robert Martwick, Democrat of Norridge, stood on their porch and introduced himself. 

Earlier, Martwick’s campaign manager had uploaded a map to his cell phone. On this evening, Martwick would visit only senior citizens in a four-block area of Chicago’s Northwest Side who had a history of pulling Democratic primary ballots. So before he knocked on a single door, Martwick knew the homeowners’ name, age, voting history and – in some cases –even the issues they cared about.

He gets the information from a Democratic voter database. It includes public information, like voting records, along with little notes collected during canvassing. If you agreed to let a candidate put up a yard sign, it’s probably in the database. Or if you talked to a candidate about –property taxes—or another issue that’s important to you, that might in the database, too.  

“I think it’s fabulous,” Martiwck said. “In the old days, we went door to door with a poll sheet and you basically knocked on a door and you had no idea who you were about to talk to. You didn’t know if they were going to be a 22-year-old woman or a 67-year-old man.”

Social networking sites are the new frontier. If you’ve “liked” anything on Facebook that might be helpful to a campaign, you can bet they’ll be using that information to reach out to you. By the time the presidential election heats up next year, don’t be surprised if you notice campaign ads popping up on your computer, tailored to your interests.

Jim Carey, adjunct professor at Northwestern University’s Medill School of Journalism, says web sites are a gold mine.

“With the evolution of social media, what we put out there, is out there. So if you are on Facebook talking about the Republican primary debates, people might be able to infer conclusions and make guesses,” he said.

The Democratic and Republican parties operate their own separate databases. The Republican database ranks voters based on “intensity.”  If you’ve taken a Republican primary ballot for the last few years, you’re a No. 2. And Republican candidates want to motivate No. 2s to make sure they get to the polls.

And both parties want to know if you subscribe to Field and Stream magazine. It might mean you’re a hunter, and that you support gun rights.

Alan Pirtle is president of the Illinois Democratic County Chairmen’s Association.

“Then that information’s kind-of kept in the database and it’s supplemented as campaigns come and go, so you take less of a shotgun approach when you work on campaigns,” he said.

Campaigns say in the future they might find it useful to look at consumer information, such as where we shop.

Professor Carey says importing all kinds of data into a database is work in progress. 

“I’m not creeped out by this stuff yet. Even with the most sophisticated political campaigns — to be able to mobilize, that is quite a challenge,” he said.

Keep in mind  Democrats and Republicans raised more than $900 million during the 2008 election cycle. If marketing companies put more information about us up for sale, there’s an eager audience waiting to buy it.