Why is there a random person in Australia threatening me on facebook?

[Jason F]

A month ago, I received a friend request from a random guy in Australia. I of course declined, but read what he had posted on his timeline. He mentioned me in a post and told me to 'pay up or it will be target practice.' I reside in the US and he is in Australia. He was following me on FB then I blocked him. Now he can't find me and I can't find him. Should I still be worried? Does this happen a lot to other people? He only posted about me once.

I realize that there are others in AUS that have the same name as me and I do realize that he might be mistaking me for someone else...

I don't know him, but what would he want with me? I'm a little shaken up about this.

Thanks for your insight.