Here’s a story which at first blush appears to be a blockage of (an often offensive) website. More information reveals that that there may have been a legitimate attack. This is a fine like that Verizon appears to have navigated well. Verizon’s statement:
Recently, Verizon Wireless security and external experts detected attacks from an IP address associated with the 4Chan family of web sites that was disruptive to our customers and our network. To protect both, we eliminated connectivity to the IP address. At no time was 4Chan itself blocked. Ongoing network security team monitoring has now determined there is no longer an immediate threat. Connectivity to those sites is being restored later today.
via Verizon temporarily blocks some 4chan sites | InSecurity Complex – CNET News.