Businesses, corrupt officials and organized crimes all using their services. Even Mexican cartels rely on them. A friend of mine who is doing importing businesses from China, rely on the shadow banking to transfer money to China to import goods from there. But these days, it is getting harder because of crack down in China. Many channels were closed. I have to say, as amazing as the Chinese shadow banking, Chinese government is even more impressive for being able to crack down on the shadow banking. But cracking shadow banking also make it harder for businesses to import stuffs from China. Many avoid legitimate way because of tax aversion, shadow banking  helped them avoiding the attention of tax collectors. Now, many reduce their import of goods from China because of the difficulty transfering money.