Judge: do not contact this woman. Man: {apparently continues harassing her} Police: {enforce} Not seeing what the problem is here. The question of whether he actually did attempt to contact her is a fact-based one for the courts... Similarly, if the woman receives a phone call with heavy breathing from the man's home phone number, it's certainly possible that he didn't do it: perhaps someone broke into his house and…
The problem is that software (and social networking software in particular) is designed to take advantage of general unfamiliarity / cluelessness and manipulate people into doing something they didn't actually intend to do. The case is legally interesting for two reasons:
1. As DanBC pointed out above, when you have a restraining order against you, you are expected to take reasonable precaution not to violate it inadvertently. However, accidentally running into your ex in the grocery store is not in itself a violation -- so long as you do not then proceed to intentionally violate the order. Could an inadvertent social networking invitation constitute a violation due to lack of reasonable precaution, or it it more like the grocery store scenario?
2. The argument from ignorance. Computer systems are frequently regarded by laypeople as being not just unknown but unknowable. Can it be successfully argued that this crazy computer stuff is just too complicated and that a reasonable person could not take adequate precaution against the whims of an unknowable computer system.
This is the adult, 21st-century version of "the dog ate my homework" -- "Google violated my restraining order". Should it go to court? Absolutely. But it's still of great interest to the HN crowd because -- depending on the technical understanding of the judge and the type of argument chosen by the counsel -- it could end up impacting the design of web services and the sort of legal arguments we see decades into the future.
Usual disclaimer: I am not a lawyer, anything I say about legal matters is probably wrong, if restraining order lasts for more than four hours consult a physician, etc.