It varies depending on the person, but I've seen: threats, fraud, assault, theft, and emotional manipulation. Isn't it harmful on many levels, when the smell of a person can clear out an entire train car? I'm not sure "respect" is the right attitude to take towards those forms of autonomy.
And, on a more philosophical level, I see kind and generous people grow callouses in their hearts because there's no real way for a normally-equipped private citizen to help these people. It's great for society to have people that will stop, engage with, and help literally anyone. We regularly take people like that and teach them to be jaded and to keep their distance. But their trust and generosity deserves to be protected as well, in my opinion.
Because those members of the community now have to deal with the fallout of a mental patient causing problems, and they are powerless to change that situation.
And, on a more philosophical level, I see kind and generous people grow callouses in their hearts because there's no real way for a normally-equipped private citizen to help these people. It's great for society to have people that will stop, engage with, and help literally anyone. We regularly take people like that and teach them to be jaded and to keep their distance. But their trust and generosity deserves to be protected as well, in my opinion.