Will a cat hiss at her abusers?

There is a stray cat in my boyfriend's neighborhood that he and I have unofficially "adopted". We feed her and play with her we've even given her a name "Putzy" but we don't allow her into the house because his dad is allergic. We see her virtually everyday. A few weeks ago the cat disappeared for a few days and when we saw her again someone had shaved her. We thought maybe she does have an owner and the owner did it. Well this week she disappeared again for a few days. When we saw her she was shaved again but this time she appeared traumatized. Her tail was also shaved. She also looked like she hadn't eaten for a few days. She usually just meows at the front door. This time she was clinging on the security like she was begging to come in. Usually when she sees me and I have my back towards she starts meowing and rubbing herself on me until I start petting her. This time she hid behind a tree and meowed. She didn't come towards me until I turned my head. Usually my boyfriend or his mom can only hold her for a few minutes and she always wants them to put her down. This time she was clinging like she wanted to stay held. To top it off, we found another neighborhood cat that had been shaved in a similar fashion to Putzy. We think there's some neighborhood troublemakers doing this to the neighborhood cats. We suspect who it is but we have no proof. I know dogs will bark at someone who hurt them but will cats do something like hiss or meow at the person who hurt them? Also if she is traumatized, what can I do for her?