Off topic: but Apple actually treats their employees really well. It's one of the highest rated employers in the US (along with Google.)
If you are talking about Foxconn, they're only a supplier for Apple, along with HTC, Samsung, Sony, Nintendo, Microsoft, Dell, HP, Motorolla, etc etc. However, Apple has taken steps to improve the working conditions of the employees in associated Foxconn factories (more than any other company has) but that could be because for some reason they take the most heat for it and every other tech hardware company associated with them (all) is largely ignored.
On topic: every company is suing every company, its the way its been for years, only now its getting more notoriety.