Actually, even the "responsible" disposal of electronics is often dumped in these places. That is, unless something has changed in the past year, which is when I last looked into this sort of thing.
But apparently scrounging through massive dumps of old electronics for minute amounts of precious metals is an awful existence. For many of the electronics they set them on fire to extract the metals, which releases terrible chemicals into the air.
But it's easy to talk about it as I sit here on my fucking laptop contributing to the problem. Ignorance is bliss, unfortunately.