That doesn't make it any easier to hear, but I'd deal with them on a more immediate basis. 
First, I wouldn't get into the business of taking away his/her favorite things in response to their attitude because for one thing, they have a lot more attitude than favorite things, and once they are out of things to take away, they have nothing to lose. The last thing I want around me is a kid with nothing to lose.

    When they give attitude, give nothing back.  If they really want something, they know how to ask for it.  For the most part when their mouth is venting and spewing venom, don't respond. They are needing a fight and in their mind, going to you the best place to get it. I can guarantee when you see that kind of behavior, they are afraid of something.  But if you were to SAY that to them, you'd just get more attitude. So get some armor and use it for non-response, while at the same time looking for those times when you get a chance to talk; those times when they are complaining about something and actually wants an answer. Let them participate in solutions, but be adamant that you don't respond when you feel you're being treated badly. 

    An important thing here is not to try to explain to them what you think is happening with them.  Make the structure for yourself, your own ideas of right and wrong.   When their behavior is relatively decent, engage.  When they get nasty, disengage.  Much of the time you can say, "You seem to be having a really tough time; let me know if I can do anything to help.  Remember, I love you." If they say something along the lines of "You can get out of my life," tell them, “No, it needs to be something you could actually do.”   And then get out of the conversation. 

    People think we can teach adolescents mature behavior by punishing them when they don't exhibit it, but we really do that by modeling it in tough times, like when they show attitude. So let them know it doesn't work, and spend some time with your spouse talking about it so you don't go crazy.   When the opportunity comes around where your kids is receptive, and it will, you must be prepared to take the time to talk them through it.

    1st, Make them part of the solution.    You this by asking them questions about what is bothering them and leading them into devising their own solution to their own problem.   If their solution turns out to be the wrong one which does not reflect your ideals of right and wrong, you simply ask them, “is this the right thing to do?  What is the down side of this?”   Remember, deep inside they have your same sense of right and wrong that you do. 

    2nd, When they hit upon the right solution, do the same thing, right or wrong. When they say right, now is the time for a touch, a hug, a compliment.  Praise works ten times better than negative comments, especially when they believe they have devised the solution themselves.

    3rd, Hold them to it.  When you see evidence that they are keeping up with what you have talked about, add more praise.  Don’t overdo it, simply say, “you make me proud,” or  “you’re really starting to grow up, that’s a good thing.”  If you see they are beginning to slip or revert to negative actions, ask another question.  “Are you doing what we talked about?”  If this elicits a negative response, look disappointed and walk away and look for another opportunity to have a productive talk with your kid. 
Rome wasn’t built in a day and it may take many talks to get through to your kids and get beyond the negative attitude. 

    There are four things you must always be.  You always have to be there and be available.  You always have to show you care, even in the most difficult times.  You always have to be willing to listen.  You always have to be the adult.