If I unfriend someone on Facebook why is it that they can still message me?

[Maria]

If I unfriend someone on Facebook why is it that they can still message me?

[Côme]

Because they can still see you, but not as a friend so they can still send messages. If you don't want them to see you at all you can block them.

[mihika m]

block the people you dont wanna receive messages from..

[Jaspreet]

They can still message you because on your profile you still have the message button. If you would like to prevent someone from contacting you block them.

[ezio]

This is why I block people.

[New Beginning]

Because they are still your friend....so they still see your messages, and your posts, etc. etc.
The way to change this is in your privacy settings. Just search around for min in there, and you will figure it out.