They stole from blues artists in their first couple of albums, and there were lawsuits which involved re-doing songwriting credits, and I guess, royalties. Dylan was a stealer, too.
But we are talking about two different things.
One is a songwriter writes their own, different song, and they use too much from an existing song.
The other is the person doesn't write a new song, they just take credit for a song that someone else wrote.