If wireless network is hacked through WPS, hacker have only access to network, means he can use your internet for surfing. I think that in case of such hack only damage is in possibly slow internet, and in the fact that hacker can do bad things using your IP address.
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Not true,
If wireless network is hacked it will be much more easier for the hacker to hack all devices on the local network.
Besides, if someone is too lazy to turn off WPS, there is high chances he forgot to change the default password for his router too.