I feel great sympathy for the homeless, after-all "there before the grace of god go I." I'm maybe 2 or 3 major life catastrophes away from being there myself. It's fucking hard out here. I donate when I can to the local shelters though admittedly that feels a bit like throwing money down a well for all the good it seems to do.
If they've got kids with them or a dog or if they're busking I'll usually send a couple of bucks their way.
I know a couple of them from working downtown and when I see them specifically I'll usually buy them a doughnut and some coffee. The sad reality is that in my experience only a handful of people are homeless due to drug use or addiction, most of them are mentally ill and should be institutionalized but the system no longer cares for them (Thanks Nixon). Another large contingent are homeless because they're LGBTQ and their families have disowned them, though thankfully I'm seeing fewer and fewer of those in SoCal.
That said, some of them are fucking scary and I can't blame anybody for trying to avoid them. I'm 6'2" and over 300lbs, so as far as "people to fuck with" goes I'm basically dead last on the totem-pole; I guess being big fat and ugly has it's advantages.