Oh, it's fairly obvious that the group is deliberately provoking a legal response, much the same way as protestors have done for years to make their points.

A reasonable solution might be working with the city and others to try and help the group open some kind of soup kitchen in an appropriate venue. They could try and get donations with this as a goal. Maybe they could work with a local church to use their property on occasion. For some years our church rotated with others to give shelter to working homeless people. I cooked up some of my famous spaghetti for them once.

In short, I agree with you that "Food Not Bombs" is probably being unnecessarily combative if their real goal is feeding the poor, but then they ARE Socialist useful idiots. :)