Ottawa's public library board will vote Monday night on whether to screen out pornography at Internet terminals in its libraries.

The board's chair, Rick Chiarelli, is calling for a system that would prevent children from accessing porn sites.

But some people are worried about what the system could mean for users' privacy.

The library already restricts Web access at some terminals. That's mostly for children, but it's up to parents to make sure kids use those stations.

Rick Chiarelli wants to change that.

He wants to set up a system where Internet users swipe their library cards at the terminals.

Cards for children would allow filtered access only.

Tom Donohue plans to speak out in favour of Chiarelli's idea before tonight's vote.

He says he'd like to block porn on all library stations for everyone, but especially for children.

"The public library has been able to provide a haven for anyone, virtually, to go to, to have a safe, enjoyable opportunity to learn. And I'm just suggesting that they want to protect that," Donohue says.

But some people worry that a card-swipe system would violate privacy.

They say the card information would remain stored on a server, along with a record of the sites the user visited.

Alayne McGregor sits on the library board. She says people don't have to worry about privacy when they look at books in the library, and the same should hold for the Web.

"Someone might be facing unemployment, but that's the last thing they want to tell people. But they want to go in and look at job search sites," McGregor says.

The library has already taken at least one measure to preserve privacy.

It's set up screens at each computer so only the user can see what's on the monitor.

Those screens also help prevent children and adults from being exposed to pornography by accident.