Hosting ranges are often blocked entirely when a likely open proxy or 0wnz0r3d box is found in them, on the presumption that edits from hosted machines are vanishingly unlikely. There are, however, more false positives than you might think ...

I just had to unblock and then reblock around 87.117.229.0/24 - which is in the middle of a hosting range, but happens to be the /24 for last.fm and includes their office proxy, 87.117.229.252 (on which user and user talk page I've put a note with their admin contact details in case of idiocy from their range). Apparently they had asked before about unblocking and been told "no" ... I don't have the details.

But false positives - either from a subrange inside a hosting range, or some old-skool type who insists on editing from his very own hosted box rather than the PC on his desk - are far from unknown with hosting range blocks. And even though hosting range blocks are generally a good idea when needed, please keep in mind the need to be approachable and to be ready to unblock as needed.

I also used the following blocking summary: "hosting range blocked due to open proxies or compromised machines - please contact in case of false positives, subranges with a contact, etc." Which hopefully should make it come across as less impersonal and tell people what they actually need to do next

- d.