Anonymous (and/or KRO) may have taken their idea from an event where Hugh Grant was handcuffed by a journalist of 101.tv (see the video).
She did get arrested for it but this did not seem to bother her very much.
In this case, it was an innocent prank, but it means that it is something open to any maniac and clearly that "journalist" acted as an irresponsible prick. In spite of her boasting, there is nothing to be proud about such act.
In the context of the CoS vs Anonymous it would clearly be an act of liable aggression.