Rate Limiting can be implemented as a way to deter high-cost actions, whether the cost of technical details like API calls, or socially expensive like posting comments, where one or two is easy to keep up with, but many can be a burden on the receiver. Well chosen, they can be invisible to users who are not actively being malicious; poorly chosen or bound to technical rather than social concerns, they can be arbitrary and frustrating limits.
Tarpitting is adding rate limits that are just not satisfiable to a malicious user, frustrating them into giving up.
Delay can be a mild form of rate limiting that makes users who are overwhelming the system or other people experience the system as slower and less pleasant to use.
Blocking most often makes users invisible to each other. In the case of public postings, it usually means that one user can’t share the other’s postings or otherwise interact with them, though they can see posts.
Muting simply ignores an undesirable user’s posts.
It’s interesting to note that more marginalized people prefer to block, and less marginalized prefer muting. There are a lot of subtle dynamics in these interactions. Given a private backchannel that doesn’t respect blocking, blocking a user will cause a harasser to escalate privately.
Private backchannel can allow someone who wishes to connect a way to do so without being public, but can also allow a harasser to privately act poorly while maintaining public good standing. Direct messages are Twitter’s backchannel; replies to author only are a mailing list’s backchannel.
Privacy groups The permission model of Livejournal, posts can be restricted to a single privacy group (a list of users) and only viewed or shared within that group.
Friending is initiating a symmetrical relationship, complete only when confirmed by the other party.
Open follow is initiating a one-way relationship, usually expressing interest by the follower in the followee.
Approved follow is initiating a one-way relationship, as in open follow, but requiring the followee to approve the action, as in friending.
Private account is disabling public visibility of the posts in an account, usually making them vet followers as in approved follow.
Upvote/Downvote are a popular way to weed out chaff from a conversation, where offtopic, rude or poorly written comments are downvoted by a community, and popular, funny, or insightful comments are upvoted. It can be problematic when the culture of a community itself reinforces poor choices, and it’s subject to gaming via social campaigns.
Reflection is the act of restating a comment when replying to it. Requiring a commenter to first restate and reflect what the original poster said before posting their reply is an interesting way to try to suppress flame wars of misunderstanding, and also increase the expense of malicious comments. I know of no system that has ever implemented this, but it was proposed by @RebeccaDotOrg and I think it’s a fantastic idea for debate where actual exploration or consensus on a hot issue is interesting.
Shadowbanning is redirecting a malicious user to a dummy version of the site to interact with where their actions will never be seen by real human beings. Often combined with tarpitting or ratelimiting.
Sentiment analysis is a way to automatically try to ascertain whether a comment is positive or negative, or whether it’s inflammatory, and whether to trigger some of the other countermeasures.
Subtweet is commenting in a chronologically related but not directly connected conversation. A side commentary, usually among a sub- or in-group.
Trackback is automated notification to an original post or hosting service when a reply or mention is generated on another site.
Flat commenting is the form typically used by forum software, where posts are chronological or reverse chronological below a topic post.
Threaded commenting is used in some environments like Reddit, Metafilter, Live Journal and some email clients where each message is shown attached to the one it replies to, giving subtrees that often form entirely different topics.
Weakly threaded commenting Threading only shown for conversation entries from followers. Often implemented client-side, given an incomplete reply graph.
Real identity can cause some commenters to behave, particularly in contexts associated with their job.
Pseudonymous identity can give stability to conversations over time, showing that the same actors are present in conversations. If easy to create more identities, can yield sockpuppeting.
Anonymous identity can create a culture of open debate where identity politics are less prominent, but can let some people play their own devil’s advocate and can launch completely unaccountable attacks.
Cryptographic identity are interesting in that there is no central authority, and they can often not be revoked (there’s no way to ban an identity systemically without cooperation). Cryptographic names are often not human-memorable, thanks to the constraints of Zooko’s Triangle. It’s possible to work around, but the systems for doing so are cumbersome in their own right.
I’m sure there are a great number of patterns I’ve missed, but cataloguing these and calling out the differences may help make us more aware of the tools we have at our disposal in creating social networks.