I would feel differently about "the media is rigging the election" comments if I wasn't concerned that a single hack could make it all become perfectly true.
Vote tallying is too decentralized for that to be a systematic threat. Hacking is obviously a concern; just not enough to undermine a landslide election at this point.
It's also funny Trump keeps throwing out this possibility. Given the current polling, I think a Trump victory would be a huge red flag as far as voter fraud goes.