A Canadian pub's pint of Guinness made a lot of Irish people extremely angry

St Patrick’s Day is serious business, and it isn’t to be messed around with. Much like a pint of Guinness.

The Railtown Café in Vancouver, Canada, found this out the very, very hard way.

The pub posted a photo to Facebook of a badly poured, very sad-looking pint of Guinness to promote its St Patrick’s Day celebrations.

Or, as the Independent.ie put it: "a thin and watery head, that's dribbling down the side of a glass".

Judge for yourselves:

People were not happy:

The pub has since profusely apologised on Facebook:

And has now had a Guinness tap installed to make sure this never happens again: