That seems like a ridiculous system.
We do not use your system so were unaware of the block. We were not notified and because you do not recheck sites, presumably many sites are blocked unnecessarily and you're relying on people reporting each one to you.
If site owners don't use your software, they would never know about the block. Users to the site would not think to come to here to report the issue because how would they know a) where to report and b) whether the infection had been cleared or not - only the site owner would know that.
Assume other companies do the same thing that you are, half of the internet would be blocked because there's no rechecking or report (you to web site owners) about the issues.
Do you seem the problem?