1. A system for encoding weightings of items of an activity stream, the weightings provided by a prioritizing user, the system comprising: a processor with an associated memory, the associate memory containing instructions which, when executed, cause the processor to perform the following operations: receive a first input from a prioritizing user to mark a first user identity with a first weighting; receive a second input from the prioritizing user to mark a second user identity with a second weighting, wherein the first and second weightings are different, the first input and second input are different sets of characters, and the first input is the character @ and the second input is the two characters @@; identify implicit actions by the identifying user, wherein the identified implicit actions include at least one implicit action selected from a group consisting of: time spent viewing a resource, age of last view of a resource, frequency of views of a resource, use of trending terms, and a collective graph from a user's social graph; identify explicit actions by the identifying user; wherein the identified explicit actions include at least one explicit action selected from a group consisting of: reading a profile, visiting a community, replying to a topic, tagging a bookmark, repeating a view, marking a favorite, prioritizing a favorite, deprioritizing a favorite, sharing the resource, and using an action requested event; determine weightings for items in the activity stream based on identified implicit actions and identified explicit actions associated with the items in the activity stream and the first and second weightings; and prioritize items in the activity stream using the determined weightings, first weighting, and second weighting.