Yesterday NOD32, normally one of the more reliable AV products, started eating the main .exe from a sourceforge project we use extensively. Irony is that the executable in question is part of an anti-malware utility.
It is literally getting to the stage where if you run AV, then you can only install mainstream, big-box software. Anything else is liable to be treated as potential malware, and deleted without warning.
NIS even takes this to the stage of being literal - If a download hasn't been seen before, it pops a malware warning and deletes it, no questions asked. I start to wonder if Symantec could find themselves in legal trouble for accusing coders of writing malware without having anything at all to substantiate that claim, not even a positive detection.
Meanwhile, McAfee operate a vetting system for unknown websites which relies on information submitted by the public. While this is nowhere near as bad as Symantec's 'if we don't know you, you catch a bullet' approach, it is still wide-open to trolls. One such troll had evidently been using a 'bot script to flag tens of thousands of websites as malware-infected. Again, this raises questions over legal liability for maintaining a system which allows trolls to block public access to legit sites.