It is indeed difficult to distinguish between those genuinely ‘forced’ to live rough and others.
During my working life, I had a chap who worked for me and was a keen member of the Salvation Army. He was concerned over the homeless and spent many of his non-working hours assisting wherever he could. A great guy.
He would never give money, but often return to those begging with a sandwich or similar. I think, given his experience, he was able to make the distinction I found difficult.
Unfortunately there are those who need our help, but sadly others seeking to capitalise.
Harrassment in any form is of course inexcusable.