It's certainly not a concern I've heard. I speak mostly with the journalistic community, being a former investigative journalist. That said, I can definitely see the concern. If sensitive information is being requested, information that, for example, falls under the national security exemption or exclusion, then there's a real reason why those records should be kept on a secure network.
However, I think this also points to the fact that there is a real need for the proactive disclosure of more records, more broad categories of records, so that we don't create this kind of congestion, so that we say all these kinds of information should be available to Canadians as a matter of course.