Face Book as an alibi?

Today my cousin wrote a post that showed she was in Australia. She wasn't. This made me think that FB could be used as an alibi. 

'But officer, I told you I was in Australia, and Face Book proves that I was. How could I have murdered a man in London?'

Endeavour

The prequel to Morse, is well cast and the plot line is fiendish, but easy to follow. I didn't guess that the opera singer was the murderer.

As I've written 2 crime novels I appreciate well written crime novels and TV series.

http://www.amazon.com/The-Doll-Collection-ebook/dp/B005E0QXES/

http://www.amazon.com/Suspicion-Points-Joanna-Stephen-Ward-ebook/dp/B00GSZIPEO/