Unless they were threatening you or your friend, you don't need to tell the police. This website was created so people could talk anonymously. My advice would be to maybe not use the chat if anonymity bothers you. There are the forums you can use instead, lots of people use it. It's a bit slower than the chat, but the same people who are regular Listeners are usually regular forum goers too.
If you think this person was harassing you, you should always report them. You can do that by clicking the flag button in the lower right hand corner above the text box. It will pop up with a small box asking why you are reporting them, and then you can explain your reason. It helps to copy and paste any direct examples of bad behaviour also.
