Thank you freetard, that was insightful.

That's an activity that can be public or only be viewed by your friends. People can participate by doing the same activity (retweeting or replying).

In this patent, "News Items" are different from status updates, which would be considered "actions". The related art section of the patent discloses that users of social networks can already see direct actions of other users, and the utility of this patent is to filter this list to dampen the noise. A more apt example would be twitter providing a list of people who have been recently followed by people that you are following, with the option of clicking the news item to also follow this new person.