Here's the link to a sedevacantist website, also found at Apologia.
From the "Introduction":
The Magisterium which is taken as authoritative here is that taught and enforced by every Pope who is clearly recognized as such by the entire Church. Since legitimate questions have been raised as to the reliability, orthodoxy, sanity, or even Papal claims regarding certain recent and current leaders of the Vatican establishment, precedence is given to the clear teachings of those reliable Popes from Pius XII on back to Peter himself. More recent teachings, if taken at all, may only be taken to the extent to which they can be reconciled to the previous teachings.
JP II is not a Pope to these knuckle-draggers; he's the "leader of the Vatican establishment."