Quick-scoping has been a long time favorite for many players in the Call of Duty series since you can easily get a one-hit kill with it - although the receiving end isn't usually happy about this. Treyarch has already made quick-scoping harder in their COD games, but it looks like Infinity Ward has removed it completely - or made it extremely hard to use.
Eric Biessman of Raven Software revealed to AusGamers during an interview that quick-scoping is not in the game anymore:
Eric: "One of the things we've done is that quick-scoping is not in the game. And that was a conscious choice, it's something that we've removed, and I think that will make a lot of people happy."
Mark Rubin, Infinity Ward's Executive Producer, has also chimed in via TwitLonger and told that the sniper rifles in Ghosts are "getting a lot of love". Sniper rifles now have dual render scopes, as revealed earlier in August, and have increased damage; to keep things balanced, the traditional quick-scoping in Ghosts has been "removed".
Mark: "However in re-envisioning sniper rifles some aspects, such as sway timing, have changed the way sniper rifles function and so traditional "quick-scoping" has been affected. Is it gone completely? Maybe. It certainly won't be viable in the way it previously was."