update: the pirate party says that their IT department is looking into the ISP problem.
update 2: this proxy seems to be located in a good position so that it is still working: http://tpb.fl.ax/
update 3: the previously listed proxy is having some issues, this alternative seems to be working fine http://pirateproxy.org.ua/
update 4: torrentfreak reports that it's a routing problem.
update 5: torrentfreak now reports that it's a ddos attack.
update 6: ddos continues, reaching day 2