Some companies (not sure about Apple) offer patent incentives to employees. Our CTO once bragged about having 150 patents. An engineer in my org decided to show him up and had 150 filed within 2 years. I think the incentives probably doubled his base salary and I guarantee none of the patents are useful or will be used.

The way I've described it, and someone working in tech patents confirmed, is that you patent to the point that it's a Mexican standoff between all the players.