From Flow My Tears, the Policeman Said (1974) by Philip K. Dick:

“Your – everybody’s – sexual aspects are linked electronically, and amplified, to as much as you can endure. It’s addictive, because it’s electronically enhanced. People, some of them, get so deep into it they can’t pull out; their whole lives revolve around the weekly – or, hell, even daily! – setting up of the network of phone lines. It’s regular picture-phones, which you activate by credit card, so it’s free at the time you do it; the sponsors bill you once a month and if you don’t pay they cut your phone out of the grid.”

“How many people,” he asked, “are involved in this?”

“Thousands.”

“At one time?”

Alys nodded. “Most of them have been doing it two, three years. And they’ve deteriorated physically – and mentally – from it. Because the part of the brain where the orgasm is experienced is gradually burned out. But don’t put down the people; some of the finest and most sensitive minds on earth are involved. For them it’s a sacred, holy communion. Except you can spot a gridder when you see one; they look debauched, old, fat, listless – the latter always between the phone-line orgies, of course.”