The Burlington library has installed a trial program to prevent pornographic Internet sites being accessed by children.
While the system was approved in May, it wasn't installed until abot three weeks ago.
Wendy Schick, head librarian, said it took some time to get the new measures in place because library officials needed legal opinions on several grey areas in the steps being taken.
"When we saw some of the questions coming up, we thought we'd better wait for the legal opinion first", said Schick.
The software filtering is also in two of the four computers at the Tansley Woods branch, and in two computers in the adult services section at Central.
Privacy screens have also been installed on the computers which don't have the special software.
The program is part of a six-month trial period, ending next April, to address concerns from parents about sexually explicit sites children have been either inadvertently exposed to or sought out while at the library.
Schick said there has been very little reaction so far and it's too early to tell how the measures are working, but expects to report to the library board next June.
The issue came to the board's attention early this year after Burlington parent David Auger expressed concerns over unrestricted Net use at the library.
His five-year-old daughter had seen a nude Playboy model, whose image had been left on the screen of a library computer.
He was joined in a plea for controls by another father, Al MacIntosh, who was looking for books with his young boys when they saw other boys calling up graphic images on the Net.
The issue became a controversy when McMaster professor David Jones argued that blocking certain sites diminishes the value of the Internet. Jones is president of Electronic Frontier Canada, a group advocating freedom of expression on the Net.
The measures stop short of having parents sign Internet-use agreements for users under 18, as suggested, and requiring children to use only the filtered computers.
"It's still up to the parents to watch them", said Schick. Library staff have been concerned filtered sites can be circumvented easily.
The grey areas that needed to be resolved centered around liability if children still happen to access pornographic sites, despite the filter; what to do if a child or other patrons print out material that clearly violates the Criminal Code; and is the library contravening the Charter of Rights and Freedoms by restricting full Internet access at some of its computers?
Schick said there is little similar case law, so legal advice has centered on library staff using "due diligence", or, doing all they can to act responsibly in such situations.