Facebook's latest security blunder is mind-blowingly serious, and it would not be unjust for the company to have many billions wiped off its value.

Losing personal information of up to 50 million people is bad enough, but also risking people's accounts with sites like Tinder, Airbnb, or Spotify was an outrageous error.

Like other tech giants, Facebook decided a while ago that having all your social-media information wasn't enough — it wanted to know what you were up to on other sites too.

It showed last week it couldn't be trusted with that information, and users should leave in droves.

Facebook's latest security blunder is a disgrace.

Facebook knows it, which is why the man in charge took a call with reporters on Friday to give the first, patchy explanation of multiple bugs that exposed information of 50 million people. Apparently, Mark Zuckerberg sounded tired. He should have sounded desperate.

The company waited for the news to filter out before revealing in a second call that, actually, the hack was much worse than anyone thought. It's possible that the breach also affected services for which people use Facebook to log in, such as Tinder, Spotify, and Airbnb. At this point, no one knows precisely how much data hackers took off with, though it's clear they would have had full access to victims' profiles.

The company's attitude is roughly equivalent to writing the shrug emoji and the caption "sux 2 b u." In a call with reporters, Facebook didn't willingly volunteer that its security breach might actually be much bigger than anyone thought; it took a question from the Slate journalist Will Oremus to tease that out.

Here's the relevant part of the transcript, highlighted:

There's a lot about the attack we don't know, but one thing is clear: It would not be unjust for Facebook to have many billions wiped off its value. The potential scale of this hack is more serious than that of the Cambridge Analytica scandal.

Even if the hackers miraculously stole very little, the fact it happened to a company entrusted with 2 billion people's information is astonishing. And it is all due to the company's early, hacky approach to growth and its apparently boundless greed.

This breach was due to a flaw in Facebook's code

Facebook explained that the hack was caused by multiple bugs in its code relating to a video-upload tool and Facebook's pro-privacy "View As" feature.

As Facebook explained it, the video uploader would appear erroneously whenever users were making use of the "View As" tool. The tool lets you see your Facebook profile from the perspective of another user. The uploader would then generate the access token for whoever's profile users were looking up. Simply put, this potentially gave hackers access to millions of Facebook profiles.

It may have been tough for Facebook to anticipate how the code for different, apparently unrelated parts of its service might interact. But if you're going to pitch for the world's private, valuable details, like their date of birth, their gender, and their phone numbers, then anticipate it you must.

Especially if you're going to spread your tentacles far beyond your own social network.

Facebook was too eager to own people's identities across the web, and now it should pay the price

Around 2010, there was a battle for our collective online identity. Everyone knows that trying to remember account names and passwords for every site you use online is unfeasible. Besides a password manager, one solution involved using a trusted site like Google or Facebook to log in instead.

As an example, here's a screenshot of Spotify's sign-up page. It shows just how easy it is to log in with Facebook rather than fill out a long tedious form:

The tactic worked. According to Quartz, citing statistics from the identity firm Janrain, Facebook became the most popular sign-in choice by far.

The deal for users was that they didn't have to remember countless logins. The deal for a service like Spotify was that users had a frictionless sign-up, meaning faster growth. And, as ever, the deal for Facebook was more data — specifically knowing what its users were up to on websites that weren't Facebook.

Was it really worth giving Facebook all that data in exchange for an easier sign-up process? Especially since Facebook so clearly can't be trusted to manage that information? Friday's news suggests not.

Security experts and journalists have been warning for years that giving internet giants this much access to our online lives is risky. This is how the comedian Baratunde Thurston put it in Forbes. He was writing about Twitter, but the same could apply to any big tech firm:

"Now I need Twitter to log in to the Washington Post's comments section, where I express my anger about the latest plot twist on Fox's Empire. If I never used Twitter again, I'd still be a Twitter user, because the company is like the school janitor with a fat ring of jangling keys to various doors in my online life."

Users should be outraged that Facebook, after lobbying so hard for those jangling keys, massively profited from their information while making a paltry effort to protect it. The company doesn't deserve billions of users' trust, and the only way to effect change is to leave in droves.

Otherwise, we're all just "dumb fucks," as a 19-year-old Zuckerberg once said.