When you have a stable of characters like Iron Man, Hulk, Spider-Man, and the X-Men it is no shock someone will be trying to make money where you're making millions. In two lawsuits Marvel was being challenged for ownership of some of these characters.
Gary Friedrich is the creator of Ghost Rider and there is no disputing that. His freelance contract with Marvel, during which he created Ghost Rider for them, and Marvel argued that meant the character and its origin was theirs, not Friedrich's. However the court seemed to think the contracts between Friedrich and Marvel weren't clear enough and a trial had been set for this November. That is until both parties settled, out of court, for an undisclosed agreement. The settlement did give all rights to the Ghost Rider character to Marvel who have already created two movies for the character but seemingly have no immediate plans for another.
Ghost Rider isn't who you normally think about when you think about Marvel though. You come up with any number of characters, more than likely, created by Stan Lee. In 1998 Stan Lee was moving on from Marvel and hoping to create new heroes under his control and thus he created his own studio called Stan Lee Media. In 2000 the internet start-up was bankrupt, and throughout the 2000's started suing former employees, including Stan himself. The company has become more known for lawsuits and money grabbing than it has for actual creating of media.
In 2012 their path of lawsuits and legal trouble continued when they sued Marvel over character rights that they thought belonged to Stan Lee, and thus somehow Stan Lee Media (keep in mind Stan Lee has cut all ties with Stan Lee Media). This time Stan Lee Media was suing Disney directly, in Colorado federal court for some reason, for about $5.5 billion to recover all the money Disney has made since purchasing and producing Marvel works based on Lee characters.
Their lawsuit was, of course, dismissed and it seems they have run out of excuses and chances to appeal. So until they come up with another reason to sue Marvel it seems even more of their key characters are firmly in Marvel's grasp.