We have a 2 years old cat we adopted from the street about six months ago. He became very spoiled, sleeps in our bed, likes being petted and gargles a lot. Also, he scratches and bites us many times. I always have marks on my both hands. It happens almost every time we pet him or try to move him away from bed or any other place like the table. I guess every now and then he does it as a play but we need to shout at him to make him stop. Then he cools and come sit next to us like an innocent baby. Other times he's just into hurting us for some reason... it doesn't look like he's playing.
We shout at him almost every time because he won't stop doing it until we make him understand we don't like it. He stops but after a few minutes would do it again. He just won't learn.
I know it's not a dog and you can't just train a cat to listen to you. Plus, it's an independent animal. Right now he's napping like a baby right next to me.