Tracing is considered as good from many people. This, however, is false.
It is true that some people trace to "learn anatomy". This obvious excuse, as it does not really help anything to just draw over the lines of another person, is only acceptable if people do not publish traced pictures though. The only way it is still somewhat acceptable if you credit the user and/or post a link to the original picture. Do not claim anything from a traced picture. No matter if you changed the hair, eyes, clothes, etc. It is not yours and it will never be.
Even DeviantART should not be that easy about tracing, as it is now. The site may say that, in some cases, tracing is allowed - But what does the original owner of the picture say? No, you can't excuse yourself with words like "If they don't want it to be traced, they can still report it", because about 80% of the people who are traced from do not know about their pictures being traced at all, unless their watchers find the art thief.
Another point of crime is selling your stolen art to other people. This is firstly cheating people who are oblivious in supporting stolen art and secondly like you would steal from a store and sell the stolen things yourself. Obviously, you don't have any talent if you need someone else to draw it before you can, and so you shouldn't try to make profit or gain popularity with traced pictures. If you sell art that is traced from someone else, it is considered a crime.
Now ask yourself - Would you try to sell a copy of a real Picasso? And would you claim it as yours, even if you are caught stealing?