He who “lets,” not he who restrains.
Oh really? Lets take a look at the Greek.
2 Thessalonians 2:7 For the mystery of iniquity does already work: only he who now restrains (katechōn) will do so, until he be taken out of the way.
katechōn - Definition: (a) I hold fast, bind, arrest, (b) I take possession of, lay hold of, (c) I hold back, detain, restrain, (d) I hold a ship, keep its head. [http://biblehub.com/greek/2722.htm]
Looks like its restrain to me from those who do the Greek stuff. Of course that would be for those who hold that God kept His promise to preserve His word for us today.