Is it at all possible to put some sort of mild safeguard into it say.... requiring a member to have been registered for at least, say, a week before they can access it? Nothing excessive. But enough to discourage people who have malicious intent from creating accounts for the express purpose of spying on people.
On that note, we have a plugin here called force ignore. This one I know the history of very well because I begged Jamie to install it. I was being stalked by someone who was collecting private information about me, intending to spread it to other people she wished to think ill of me. I personally felt extremely threatened by it since this person had threatened my family before. Force ignore prevented her from viewing any of my posts. In a merge, something like this would have to be caried forward and the existing blocks kept in place. but obviously only ever implemented in very serious situations such as stalking like me case. We couldn't find a valid rule that justified banning when someone has a stalker.
You know, I'm interested in this "stalking" tool you talk about. As someone who has actively hacked and found info out about people like a decade ago, I am pretty sure there is no addon that can actually block someone who cares to stalk you from actually stalking you. When you're on the internet in a public place, there are always work around and they are almost always extremely easy to do. Of course the easy thing is to never put any information you don't want public... public. If they are access private information, that's different, but you probably shouldn't keep private information on a message board profile, etc.
As for the "one week of activity" or what have you - certainly doable. Easily so in fact. But, what should the REAL barrier of entry be? We use to have a subset forum for such private conversations that the public was aware existed, but they had to ask to gain access and access was granted on an indviidual basis. SOrt of like NeoGAF, except the conversations aren't public. It was a better way of filtering out bad eggs who can't handle such personal chatter than a arbitrary time period.
Would love to discuss this stuff further.