JK Rowling says to photograph women in toilets just in case they’re transgender
(www.lgbtqnation.com)
There are cases.
Trans people are people and can be abusive or assault others just like everybody else. Trans folk have to deal with more mental health issues than the average person. I’m just guessing, but it might make them more likely to be victims of violence or to abuse others.
These are just a few from the first page of DDG results.
https://nypost.com/2023/06/01/oklahoma-parent-files-suit-after-daughter-was-beaten-by-trans-student/
Of course this is only anecdotal.
Bathroom restrictions don’t protect against abusers of any gender. People should feel safe using a bathroom regardless of their gender or sexuality.