Since it seems that all of the comments on this question are woefully bigoted, allow me provide the flip side of the debate... if, that is, you view the health and well-being of transgender youth as a "debate."
I am a transgender person. I did not wake up one day and decide that I didn't want to be female; rather, I spent my whole life not feeling female and wondering if there was something wrong with me. When I stumbled across the concept of being non-binary on social media, I finally had the means of understanding myself.
What the prior posters fail to grasp is that transgender people like myself aren't trying to tear down society, destroy gender, or promote some type of "sinful" or "perverted" life style (only if you insist, and it does sound like fun). We're just trying to live our lives.
I can guarantee you, going through the risks of being disowned by one's family or murdered, and facing daily psychological harm by being seen as the wrong gender at all times, is not some "decision" we come to thinking it would be "fun" to peep at girls if we're trans girls. I don't have a locker room for myself, so I use the women's. Am I trying to molest anyone? No. In the 1 year I've been out as trans, I've had no desire nor made no attempt to do anything inappropriate towards a woman, in a locker room, bathroom, etc. But if I were to use the men's, I could get beaten, raped, or killed. (I notice all the answers on here seem to be from cis men? Y'all are the real danger to women, trust me, not us.)
Transphobia kills. It always has, ever since the white settlers encountered Two-spirit natives and decided they had better "act normal" or die. It causes us to commit suicide in higher rates than the norm, and be murdered in higher rates, as well.
I wish all of you commenting here had given a damn about Leelah Alcorn before she had killed herself, but I can imagine you'd probably treat her no better than her parents did, who buried her as a boy.
In conclusion, you're all pathetic.