As a IT person and from a history of analyzing user's internet activity, the average employee surfs the internet from work 2 hours a day on average excluding lunch breaks. Its common for employers to have internet filtering appliances to help limit access to sites that are non-work related in order to cut down on misuse of time. It's not just an IT person sitting at a desk with their finger on a button and watching internet activity. Its an appliance such as a Barracuda that is blocking the access.
Now, why they are blocking "Computers/Internet" is beyond me but "Illegal/Questionable" is logical. However, some appliances aren't perfect and often have false positives. We run into this all the time and have to add exceptions to the device. Clearly the site isn't illegal or questionable so it may be a false positive by their appliance. Contact your IT team and ask them to query the appliance and see why the site is being blocked and if they can add an exception.
