The 30 year old was acquitted by a jury last month of raping and falsely imprisoning the woman in her home on the same date.
It's the first prosecution for criminal damage to a social media account.
The man - who can't be named because of the rape charge - was charged under the Criminal Damage Act 1991 which carries a maximum penalty of ten years in prison and a 10,000 euro fine.
Mr Justice Garrett Sheehan called it a reprehensible offence which seriously damaged the woman's good name but said that fortunately the status was quickly spotted and taken down.
He said that a financial penalty was the most appropriate and imposed a 2,000 euro fine.