There have been various reports in the UK press in the last few days (this one included) of a case in the Australian Workplace Tribunal which is stated to have found that unfriending a colleague on Facebook can amount to bullying.
In fact, that is not really what the decision says at all.
The case arose from a dispute in an Estate Agency where one Ms Roberts complained about the way her properties were being displayed. The wife of the principal, Mrs Bird, made some disparaging comments about her and when Ms Roberts went to Facebook to see if it was being mentioned there she was upset to discover that they were no longer "Friends."
The Tribunal in fact found that there had been a sequence of events over a period of two years which as a whole amounted to bullying.
In the employment law of England and Wales there is, as such, no legal right not to be "bullied." It is however a term of all contracts of employment that the employer will not without good reason behave towards the employee in a way which is calculated (intended) or likely to destroy or seriously damage the relationship of mutual trust and confidence. If an employee resigns because of a breach of this term this is capable of amounting to constructive Unfair Dismissal.
Simply "unfriending" someone would be unlikely in and of itself to amount to a breach but context is everything. If it was part of a pattern of unfriendly behaviour then it could be the "final straw" that justified resignation. If it was done in an ostentatious manner which was done with the express intention of upsetting someone then that could similarly amount to a breach.
If on the other hand a manager unfriended someone because it was inappropriate to be friends with a more junior employee at a time when the former was going to be dealing with a disciplinary matter relating to the latter then that would be perfectly reasonable.
Of course, this perhaps all begs the question as to whether it is sensible to be Facebook Friends with your boss in the first place, but that is another story.
Interestingly, it appears that the Tribunal in Australia did not have any legal power in this case to award compensation.