From "The Pastor's Corner" of the website of the United States District of the SSPX:
“1,000 soldiers fall to the left, 10,000 to the right”. This Scripture quote from Psalm 90 reminds us that false brethren (those on the right) are more dangerous than true enemies (those on the left)...
***After the betrayal of the cowards and the weak, there came the defection of the sedevacantists who tended to divide themselves indefinitely. Then came that of the children of Archbishop Lefebvre, their own spiritual father, who left him for the mirages of the roses and lilies of modernist Rome. These are as so many tombstones strewn in the cemetery of the “War Veterans of Tradition”; tombstones of mute dogs, forever forbidden to bark at the madness of our poor Church authorities for the sake of a meager place in the sun and a piece of paper proving them to be “inside” the Catholic Church. Their name is legion: The monastery of Le Barroux, the Fraternity of St. Peter, Bishop Rifan and Campos , the Institute of Christ the King, the Institute of the Good Shepherd...
Then, to complete the picture, you have half-traditional priests, operating under the Pope’s gracious motu proprio liberating the Mass of all time. These priests are unfortunately halfway between the old and the new in more things than liturgy, and this reality does not make them so palatable to us. Can we really entrust our souls to someone who is meant to be our father, when the first condition is that he truly be a father and an example for us and our children? Woe to those souls who give themselves entirely or even halfway to unclear and untrustworthy leaders. Who would let his daughter jump in a car driven by a madman? Is this not what many of our friends are doing when, for mysterious reasons, they decide to pick-and-choose which traditional church they want to go to?