In a recent entry, solderpunk wrote about walled gardens and Internet communities[1]. solderpunk's thesis is that some of these services which require membership are "bad" or "evil", while others are not. There is an argument to be made that some of these services are evil because they (or the entities that run them) are ethically poor, actively malicious, or detrimental to some of the people who engage with them. However, I'd like to investigate the concept of the walled garden itself to arrive at the "more nuanced understanding" that solderpunk is looking for. I aim to understand this in terms of whether the expectations of different communication channels are upheld. Any communication can be thought of as being, to a varying degree, private or public. Private communication is communication we engage in with certain, selected individuals. A conversation had at home, or a phone call to a friend is intended as private. Public communication is communication where we send messages with the expectation that many people can receive them, and that we cannot not generally control who these people are. A blog post, or calling talkback radio, or publishing a book, is intended as public--the intent is for anyone to be able to read or listen. Between private and public communication is in-group communication: While a group of people (who you have not necessarily selected) can receive your messages, you can have reasonable expectations that these people meet certain criteria. Instances of in-group communication would include discussing staffing issues at a managers' meeting, or performing a stand-up comedy show at an R18 venue. To continue solderpunk's example, SDF provides tools for all three types of communication, including notes and email for private communication, com and bboard for in-group communication, and http and gopher for public communication. Private communication can take place both with group members (e.g., notes) and non-group members (e.g., email). There are two important factors here which distinguish this service, which (we argue) is not evil, from others, which (I shall argue) are. Firstly, group membership is required of the interlocutor or recipient only if you wish to communicate specifically with group members. Secondly, the level of privacy or publicity provided by each communication channel is robust. Private communication channels are not robust if the expectation of privacy (that is, the ability to select one's recipients) is not upheld. In-group communication channels are not robust if the expectation of group membership (that is, that recipients meet certain criteria) is not upheld. Public communication channels are not robust if the expectation of publicity (that is, the ability for any recipient to receive your message) is not upheld. A walled garden (or in fact, any communication service) becomes evil (unethical, malicious, and/or detrimental) if it violates any of these expectations. The most common (or at least most salient) violation of communication expectations is the violation of privacy. This happens when a third party (such as the communication service provider) gains access to and makes use of a message intended for a different recipient. An example of this is Skype, where the company itself makes use of messages sent through the communication channels it provides but that are intended for other recipients. (The fact that Skype makes note of this violation does not mean that it is not a violation, as users arguably intend their messages to be private.) Private communication is not a form of in-group communication, as there is no expectation that recipients must be members of a certain group, only that they be selected by the message sender. Therefore, I argue that the expectations of private communication can also be violated if group membership is additionally required for communicating with certain, selected individuals. The public telephone network does not violate this expectation: Although I must be a member of a group (by subscribing to a phone company), I can exchange messages with people who are not members of this group (I can make calls to people who subscribe to different phone companies). In contrast, for example, Verizon's email service violates this expectation as it rejects certain communication from non-group members (specifically, messages from users of some other email providers). In relation to Internet communication, this can be seen as a class of violation of Net Neutrality. Violation of in-group communication occurs when non-group members are able to access messages intended only for group members. As with private communication, this may be violated when a third party gains access to messages not intended for them. However, it may also be violated, for example, when the requirement for group membership is not upheld or not clear, such as the oversharing that can result from Facebook's confusing (and highly criticised) "privacy controls". The expectation of publicity is violated when restrictions (in the form of group membership requirements) are imposed on recipients of communication that is intended as public. If I wish to publish documents on a Web site or Gopher space, I need to be a member of some group which provides an appropriate hosting service (or alternatively provide this service myself). However, people can access these documents without being members of the same service. A service which violates this expectation is Dropbox, which, while purportedly allowing members to send computer files to other people over the Internet, makes receiving these files unnecessarily difficult for people who are not in-group. We have considered a walled garden here as an entity that provides communication services and has membership requirements. Such barriers to entry are not inherently evil, but a walled garden can become evil in any of these ways if it violates its users' expectations about the services it provides. [1] gopher://sdf.org/0/users/solderpunk/phlog/two-walls-good-four-walls-bad.txt