The long-discussed testing of ISP-level Internet filtering, with six companies taking part: Primus Telecommunications, Tech 2U, Webshield, OMNIconnect, Netforce and Highway 1. Primus is the largest of those, and the absence of top-tier ISPs (like Telstra, Optus or iiNet) has attracted much comment. A test involving smaller ISPs might not be very conclusive, but look on the bright side: it could go so badly that the plan gets abandoned altogether. We can only hope. Meanwhile, If you are using one of the participating ISPs and have opted in for testing, share your experience in the comments.