Let's start with the good privacy feature that has been build into the current version of lists - the ability to mark lists private or public. This is a sensible idea and has been implemented in a way that is easy to use (although we would prefer it if the default was for lists to be private rather than public - but this does seem a little like splitting hairs!)
Unfortuntely - the way that the lists have been set up currently are open to a number of forms of abuse. The primary reason for this is because a user does not have to authorize being added to a list. i expect that this is a useful (and necessary) feature for the top-ranked users, who could be added to hundreds or thousands of lists and would not want to have to accept every single request to add them.
On the other hand - this does mean that people can add you to lists without your permissions - and some of the following could occur:
1. You are added to a list that gives away some information which you didn't want shared (e.g. parents of XYZ Middle School) - this could be significant information leakage, dependent on which lists you are added to.
2. You are added to a list that isn't relevant to you (not so bad)
3. You are added to a list maliciously or acciedentally that is damaging to your reputation (e.g. Registered Sex Offenders)
There needs to be a trade-off here. On one hand, we could subject everyone to "list spam" and render the feature next to useless. On the other hand, there could / should be some better tools to manage what lists you are on, and to remove yourself.
Although lists "follow" you in the same way as people do - you can't seem to block the list, just the person who created the list.
It's a brave new world out there. Would be interested to hear others experiences and thoughts on this.