One more time.
"A cursory check of social media is standard in my industry"
"Don't get me wrong, it isn't the be all and end all, but it's a consideration even if a sub-conscious one."
"I'm not saying that you won't get the job, I'm saying that it's certainly a con to be taken into consideration and all other things being equal, you'd lose out."
"it should be treated as public rather than private and as such, anyone with a professional aspect to their life, should act on it as they would like to come across at any other point"
I'm not saying that you will be hired or permanently on the brew for the odd 'fuck' on Facebook. I'm saying that your social media will likely be (very briefly) checked and if the first things that pop up are littered with swearing, the check will get a little deeper and it will be a (however minor) con against hiring you.
I've just asked around the office who uses Facebook and the general response was "do I fuck". My boss used the gem, "No, but IT monitor your LinkdIn and if any of you cunts update it, I'm firing you before you jump ship!" I absolutely believe the first part.
I work in a large (PLC) business consultancy company. We deal with very large contracts. I am an IT specialist but tend to liaise with clients more. Some coding but I spend too much time trying to keep up with the newly qualified bods in that area!