As Americans collectively process the president's bout with COVID-19, they are solidifying Twitter's role as both our national water cooler and key source of official and unofficial information.

Why it matters: Twitter's architecture makes it a natural forum to turn to during key news moments, and the crisis has shown the platform's continuing value in that role. But the moment is also displaying many of the service's weaknesses — a vulnerability to rumor and speculation, security gaps, and inconsistent rules enforcement.

Driving the news:

• The president first revealed his positive test for coronavirus on Twitter at 1 a.m. Friday. Official confirmation came quickly, but still several minutes later. Subsequent videos and statements from the president have also come via Twitter, though he's tweeting a lot less than has been typical.
• With the public receiving limited and contradictory information on the president's health, Twitter has also been a place for medical professionals to analyze the information coming out about Trump's health.
• With many Trump campaign and White House staffers themselves out of the loop, Twitter has also served as their main source of information, as the Wall Street Journal and others report.

The big picture: Facebook has also been an information source during the crisis, and has taken action against some posts connecting the president's illness with election-related misinformation.

• Even TikTok has played a role, as Kellyanne Conway's daughter used that service to announce her mother's COVID-19 diagnosis, which the former White House adviser then confirmed on Twitter.

ButTwitter has played the most central role for several reasons.

1. It is public by default.
2. It favors real-time posts, unlike Facebook whose algorithm weights engagement over timeliness.
3. It is the president's go-to medium, and is widely used by journalists, politicians and medical professionals.

People used Twitter to share everything from their experiences with dexamethasone, the steroid Trump is on; to how both parties ought to handle the situation; to expressing their disapproval of Trump's Sunday SUV ride.

Yes, but: Baseless, evidence-free conspiracy theories have also flourished about the president's health, including suggestions that Trump's illness isn't real.

• The "Trump is faking it" conspiracy theory is spreading widely on Twitter and Reddit, according to data provided to Axios from social intelligence firm Zignal Labs, which analyzed the top storylines related to Trump’s COVID-19 diagnosis from 12:01am on Oct. 2 onwards.

My thought bubble: As I and others have pointed out since before Trump took office, the president's continued reliance on Twitter to convey messages that have a national security impact is a risky practice.

• Among other reasons, there is no sure-fire way to know if his account had been compromised.
• In this case, the tweet in which the president confirmed he had COVID-19 was authentic. However, a tweet from a hacked presidential account would look identical.

Also, with Twitter and other social media platforms, you can never be sure whether the account holder or a surrogate is actually writing a post.

• Given the sparse medical info the public has received and concerns over the president's fitness to carry out his duties, our ignorance of who's doing the typing could become a more troubling problem.