Update: Apple released a message to its users on Thursday, addressing concerns about iPhones after the company confirmed it slowed certain models to protect aging batteries. Apple apologized for the “misunderstanding about the issue” and assured customers that it had “never — and would never — do anything to intentionally shorten the life of any Apple product.” It also promised to replace iPhone 6 or later batteries for $29 — a $50 discount. Read Apple’s full statement here. The original story is below.

The delay in typing messages, or the lag in loading my mail on my iPhone, has been explained. Apple has confirmed that it does deliberately slow down the operation of older iPhones, and says it is doing so to prevent the devices from shutting down because of aging batteries.

Apple says it’s doing this to protect your phone. As the lithium-ion batteries in the phones age, they can’t handle processing demands at the same capacity, which causes the phone to shut down unexpectedly. The company released an update to stop those unexpected shutdowns, which also means the phones work a little more slowly.

But the revelation — or confession — that Apple is purposely decreasing phone speed fed into a conspiracy theory that’s been circulating for a while on “planned obsolescence.” After new products are released, the theory goes, Apple intentionally messes with your iPhone, frustrating you and forcing you to shell out money to upgrade.

The data on Apple slowing down older iPhones doesn’t necessarily mean the conspiracy theory is true. A relatively recent change to its operating system prompted the slowdowns. But the system update demonstrates why the conspiracy theory keeps circulating: It took an independent investigation by an expert and a viral Reddit post to get Apple to admit what had happened.

This whole saga began with a Reddit post — and ended with an Apple confession

People who owned iPhone 6, 6s, and 6s Plus devices complained earlier this year that they were spontaneously shutting down, even though they had sufficient battery. This was usually happening during “peak current demands,” when you’d be doing something on your phone that required a burst of power — like in the middle of a game, or downloading an app.

Those users had to plug in and recharge their phones in order to get them back online. Apple acknowledged the bug and introduced a fix in an update to its operating system software, iOS 10.2.1, which the company said would largely remedy the issue. Phones no longer shut down, but according to users, they did slow down.

Then last week, a Reddit post blew up that suggested the iPhone battery might be to blame for these slowness problems.

John Poole, founder of Primate Labs and Geekbench developer, seized on this hypothesis, and pulled together and compared data from the performance testing Geekbench had done on users’ iPhone 6s and 7 devices.

He analyzed all that data from a sample set of approximately 100,000 phones, and said he had tens of thousands of results across different versions of iOS — specifically, he looked at iOS 10.2.0, the version before Apple fixed the shutdown bug, and iOS 10.2.1, which was released after the fix. (He also looked at later versions, including 11.2.0, which is a more recent software update.)

His analysis revealed that processors did slow down after the update meant to fix the shutdown problem, that the problem was widespread, and that, as he put it, it was “likely to get worse as phones (and their batteries) continue to age.”

Poole, and others, speculated that the link between old batteries and slower performance had to do with the initial iPhone 6 glitch, and Apple, in fixing that, slowed down the system to avoid overloading the batteries. (He also noted that iPhone 6s users who replaced their batteries had faster phones.)

And though the iPhone 7 never had those spontaneous shutdown issues, Poole’s results indicated that it did slow down in later updates — a sign that Apple was doing this across its models.

“Once the phone is shut down, the battery is in a state where the only way to get the phone back online is to plug it into a charger. If you’re out with your phone on the go, that’s clearly not a great situation to be in,” Poole said.

“So Apple, with this fix, basically limited the processor from overtaxing the battery. But the flip side of that is now the processor can’t run as quickly as it might in a new phone with a new battery.”

Poole’s data got a lot of buzz, and finally Apple responded:

Our goal is to deliver the best experience for customers, which includes overall performance and prolonging the life of their devices. Lithium-ion batteries become less capable of supplying peak current demands when in cold conditions, have a low battery charge or as they age over time, which can result in the device unexpectedly shutting down to protect its electronic components. Last year we released a feature for iPhone 6, iPhone 6s and iPhone SE to smooth out the instantaneous peaks only when needed to prevent the device from unexpectedly shutting down during these conditions. We’ve now extended that feature to iPhone 7 with iOS 11.2, and plan to add support for other products in the future.

So Apple basically confirmed Poole’s results and redditors’ theories. “With this large of a sample size, I’m confident the numbers we have produced are accurate, and also the fact that Apple has verified,” Poole said. “It gives me a warm, fuzzy feeling that we didn’t screw up our analysis.”

Case closed?

To many, Apple’s admission seemed like proof of the company’s grand conspiracy to force people to keep buying new phones. But Apple’s explanation, and Poole’s, suggests the opposite — a slower phone is better than a glitchy one that suddenly shuts down. It’s more likely that people would end up replacing a phone that constantly shut down than a phone that’s a little slow.

Poole said the battery explanation is legitimate. Lithium-ion batteries age over time. That wear and tear makes them less capable of meeting the power and processing demands in the same way as a youthful iPhone. This is also intensified with the iPhone, which has a particularly speedy processor — which puts even more stress on the batteries.

“I have a feeling this is a weird confluence of Apple’s desire to have very thin, very sleek phones coupled with also having the fastest processors in the industry,” Poole explained.

“The fact that Apple is using these very fast, very high-end processors that they design — whereas Android phones might use slower processors — these fast processors are putting a greater demand on the battery,” he added. “I think that’s why it’s a problem that’s particularly unique to the iPhone.”

Yet Apple had not been forthcoming about slower speeds until this week, and, as CNN points out, the company doesn’t regularly notify you if your iPhone 6 battery is in poor health. (The company did alert some iPhone owners and replaced batteries for certain iPhone 6 users whose shutdown issues couldn’t be fixed by the software upgrade.)

Apple also announced the fix to the shutdown glitch early in 2017, and aging batteries were assumed to be the cause. But it didn’t mention anything specifically about slower phone speeds. That shadiness feeds the rumor mill that Apple is subtly trying to nudge you to get the shiny new iPhone.

That conspiracy existed long before Poole’s analysis. Google searches for “slow iPhone” spike around the time a new model comes out. In 2013, Catherine Rampell wrote in the New York Times that after the iPhone 5 came out, she “noticed that my sad old iPhone 4 was becoming a lot more sluggish”:

The battery was starting to run down much faster, too. But the same thing seemed to be happening to a lot of people who, like me, swear by their Apple products. When I called tech analysts, they said that the new operating system (iOS 7) being pushed out to existing users was making older models unbearably slow. Apple phone batteries, which have a finite number of charges in them to begin with, were drained by the new software. So I could pay Apple $79 to replace the battery, or perhaps spend 20 bucks more for an iPhone 5C. It seemed like Apple was sending me a not-so-subtle message to upgrade.

Tech bloggers have generally knocked the idea that Apple is torturing you with a crappy phone to get you to buy a new one. But they do say that newer software upgrades can mess with older phones because the new software is designed for, well, the newest model — the one with the fastest processor and the freshest battery. Usually Apple figures this out, and releases updates to fix as many glitches as possible. But it can’t remedy everything. And in the case of the iPhone 6 shutdowns, it had to find workarounds.

The counterpoint — well, maybe those phones shouldn’t be updated with the latest software if they are not fully compatible — isn’t totally convincing. As Rene Ritchie put it in a 2014 iMore article: “Phones and tablets that never get updated avoid the potential for slow down, but they also avoid getting new features, security updates, and the ability to run apps that require those updates.”

Apple’s latest admission probably won’t quell the conspiracies — or please customers. A class-action lawsuit, alleging breach of contract, was filed on Thursday in federal court.

There’s also the fact that Apple doesn’t make it easy to change or replace the battery. (Apple’s battery replacement costs $79 — not cheap, but not the cost of an iPhone X.)

But Poole said if it were easy to replace, then the iPhone wouldn’t be an iPhone. A replaceable battery would have to be thicker, and the phone would have an obvious battery cover. “I think it’s the trade-off that Apple makes,” he said. “They want the very thin, very light, very sleek phones. And by making the battery non-replaceable, they’re able to accomplish that.”