They watch. Watching is simple. Watching is what they are good at. Not in person of course, as computer surveillance tends to be more their style. Then again, they like to watch in person sometimes. Just not all the time. They have dynamic and undetectable methods of surveillance used by everyone from the ordinary passerby to the Central Intelligence Agency and beyond. Of course, they don't watch every single thing that every inhabitant of Rosewood did; that would prove pointless and time-consuming. They only watch things and people that are necessary for achieving their clear-cut aims. Nor are they Peeping Tom in the literal or sexually perverted sense - omniscient would be a more accurate description. Like Big Brother.
They could enjoy watching their victims squirm. It could be fun to witness said victims desperately seeking information that they would never retrieve, and see them yearning for answers that were unattainable. However, what separates this them from the others is their emotional attachment. Or rather, lack of. They aren't psychopathic or sociopathic; nor do they get off on the things that they do. They could feel, if they choose to. Though they simply make a rational decision every day so as not to allow feelings to cloud their judgement. To avoid empathy. Emotional detachment makes everything significantly easier.
They don't try to delude themselves into thinking that they are noble or even decent, or that their heinous actions are anything more than just that - heinous. Because they aren't. They aren't a part of some kind of mad quest for the greater good. They are selfish. Some would say that there were better ways to spend time than achieving such aims, but they disagree. Their aims are integral. They will never be caught. At least, they shouldn't be. They have taken all necessary precautions. They aren't rash. They think through things properly before doing them. The majority of the time, anyway.
Maintaining anonymity is necessary for everything to occur as it should. No name, no face, no identity. Just a letter. One letter. 'A'.