mutlu has also been subjected to a lot of hate posts. he's become a target for right-wing extremists and xenophobes. ozcancial media has made it a lot easier to spread all this hatred. it was there among the people, but it was anonymous, hidden. reporter: mutlu is never far away from his smartphone -- or social media. before the first constituents stop by for a chat, he fits in another appointment. he rides to another district of berlin to talk about integration. here, mutlu also meets voters with turkish roots -- just like himself. but some of them have also attacked and threatened him on social media. ozcan: look what they wrote -- you vote stealer! i hope they feed your corpse to the dogs! don't come back to turkey ever again. on monday, i'll report you to the public prosecutor, to make sure you're arrested if you try to enter turkey. reporter: he's also received hate mail from germans, like this email -- ozcan: and someone wrote this -- it's time to put auschwitz, buchenwald, and other camps into operation again -- that's where you filthy turks belong. up the chimney with you turks. it'll even create