90 year old father newly addicted to porn and people are refusing to care for him now. Any advice?

What's very common with dementia is something known as ISB or Inappropriate Sexual Behavior, which is what your father is exhibiting. There is medication available to 'curb his appetite' so to speak. You need to call his PCP and alert him to what's going on. Your dad needs an evaluation for dementia/Alzheimer's and you can go from there.

If you take away his computer, he can likely find more porn on his tv set if he has cable.

I wouldn't be threatening him with jail time for sexual harassment if it were me. I'd find the source of what's happening to him instead. Denying his wrongdoing and being argumentative/not believing what's being said to him are all signs of dementia as well. So if he's suffering from this, he's not realizing that what he's doing is not 'socially acceptable.' In his mind, it's perfectly fine and it will STAY perfectly fine until medicine helps him think differently.

Wishing you the best of luck.

What does he say when you tell him that he is going to go to jail for sexual harassment?

Has anyone told him to stop and that his behavior is unacceptable?

I agree, he has seemed to have lost his filter. This is a sign of Dementia. Being inappropriate with a Drs nurse in a public setting, is a sign.

Waterfallz, porn addiction is extremely common. You can sign up for a filtering service to keep the sites unaccessible. Just google it and you'll find what you need. But eventually you'll need to be more and more involved because he can be lured into online gamgling, phished, or have scammers find him and drained of his money.

If he is touching and showing people the pics, he is displaying symptoms of dementia. Please do a little research to familiarize yourself with some of the behaviors. Make an appointment with his doctor and accompany him. Pass the doc a note requesting a cognitive exam and they will be glad to oblige. Then the results will help you know how to provide him the appropriate care.

If he has no dementia, but has a porn addiction and is acting inappropriately, he needs a therapist, not an MD. He's lucky they haven't reported him to the cops...yet. Or, like Vegaslady suggested, the computer can "be out for repairs". Hopefully he doesn't have a smart phone or it will be pointless. Good luck!

Can his computer magically break? Or could he just get another? Probably need to discuss this with his doctor.