Facebook users already had the ability to search for updates posted by their friends, but Zuck and company have now decided to extend the search function to capture all public posts.

Facebook puts it thusly in its blog:

When something happens in the world, people often turn to Facebook to see how their friends and family are reacting. Today, we’re updating Facebook Search so that in addition to friends and family, you can find out what the world is saying about topics that matter to you …

The move will dramatically increase the pool of up-to-the minute content that users can search. It may give Facebook the Twitter-like ability to show users trending discussions and events that are journalized on the platform in near real time. Since Facebook posts are personal and often react to events or trends, the new search capability could pose a threat to products like Google Trends.

Search on the monster of all social media platforms was once geared toward searching for people, but it’s shifting toward the actual content of posts. Facebook says it now hosts more than 1.5 billion searches per day, and has more than 2 trillion posts stored in its servers. Two trillion.

Facebook is clearly trying to offer something like Twitter’s new Moments feature, which marketers are already clamoring to exploit.

Here’s how a Moments-like story can be assembled using universal search: As Facebook puts it, interesting public conversations are often tied to a link about a certain trend or event. “With one tap, you can find public posts about a link, see popular quotes and phrases mentioned in these posts, and check out an aggregate overview of sentiment,” Facebook wrote in its blog.

“This feature is a first step — we look forward to people using it and giving us feedback so we can make it even better.” That’s an important message — Facebook intends to continue building the feature to gather more content elements around important links.

Facebook’s universal search may affect digital marketers by increasing the number of searches Facebook members do, which could provide a fuller picture of users’ interests and intent.

Facebook isn’t stepping over any privacy lines here, because search is still confined to posts that users have designated as public. “Friends only” posts won’t show up in search results.

Universal search is rolling out to English-speaking audiences in the U.S. today on iPhone, Android, and desktop.