Zac counterplay

So i have started to nice more and more Zac's playing in games and noticing more and more how strong he is. He always seems to be able to get ganks off constantly and can always dive from far away onto you. Thinking about it, it seems this more about our allowance of wards. His jump range is massive and with a limit of 6 wards on the map early game and maybe 9 late game, its difficult to actually play against him as we cant ward over a wall while defending cause we had to ward a bush somewhere else to do it. What do you people suppose we do?