When i was at Uni there was a homeless bloke who used to sit at the entrance to the alley towards my house.
I always gave him chocolate or chips.
Once, as i walked down the alley he began to follow me. Being suspicious i turned round and told him that i would break his neck if he came closer...then he explained that he wanted to see me get home safely because i was nice to him.

After that, i chatted to him a bit and we talked about why i gave him food and not money. He was more grateful for the hot chips on a cold day.