The metal will block some Wi-Fi signals, but not completely, because the gaps between the bars are too wide to block it all.
2.4 GHz also happens to be the frequency that microwaves operate at. Every microwave oven has that mesh in its window, because those holes are precisely the right size to let you look through while still blocking all the 2.4 GHz emissions inside the box.
Wait, they're going after the NFL, too?