Technically that is possible. Whether your local legislation allows ranges to be blocked (and on what basis) is another issue. At least the Finnish court order

Technically that is possible. Whether your local legislation allows ranges to be blocked (and on what basis) is another issue. At least the Finnish court order that ordered a block on TPB IP's had individual IP addresses in there, so at least another court session is required to change the IP's or make a whole range blocked. It's worth noting that the Finnish ISP's were not happy to put any filtering, DNS or IP, in place and will not add any blocks voluntarily.