Absolutely. Long term shit, and you don't even need hard to get equipment to generate it. A fucked up speaker could be giving it off constantly while turned on, and you wouldn't know it unless you had monitors providing a readout. Imagine- you have a political opponent running against you. You want him to lose the race, obviously. So you have speakers planted around his house covertly, hidden, set to generate infrasound constantly. Every moment he's home, he's subjected to it. Over the course of months, he'll become a paranoid, nervous wreck, his sleep all fucked up. He'll be seeing shit, hearing shit, feeling shit that's not there. And then he'll begin to seem more and more unhinged. He'll look like shit at all of his speeches. Or, think on a bigger scale- you have a population that you want to fuck up, all living in the same city. Set speakers up all over the place generating infrasound. Soon, you have a population all agitated and paranoid, lashing out at each other, mass psychosis may manifest as they see "hauntings" and other nonsense. A lot of older buildings with older ventilation systems have problems with this already. Interesting fact- some things in nature generate infrasound. An example would be a lion's roar. I wonder if this bizarre weakness we have to infrasound is an evolved trait that was developed over the centuries to act as an early warning system, to set us on edge when the distant march of thousands of hostile enemies was generating this noise, or predators, or w/e. In that case, it's good that it makes you paranoid and worried, because then you'll be able to combat the threat. But when there is no threat, it'll drive you mad.