iPhone 4S The iPhone 4s. ZONEofTECH

Apple's latest mobile operating system slows down the iPhone 4s so much that it's basically unusable, according to a lawsuit filed in New York this week.

The class action lawsuit, which was first spotted by Apple Insider, is seeking $5 million from Apple.

The suit was brought by a single Brooklyn man, Chaim Lerman, but any iPhone 4s users in New York who updated to the latest OS (iOS 9) are eligible members of the group lawsuit.

When Apple first announced iOS 9 in June of this year, it said the operating system was specifically designed to run properly on older iOS devices like the iPhone 4s and iPad 2 - a nod to the growing number of iPhone users who rely on older, still perfectly good iPhones instead of updating every year or two.

But the lawsuit claims iOS 9 "significantly slowed down" the iPhone 4s, "leaving the Plaintiff with a difficult choice: use a slow and buggy device that disrupts everyday life or spend hundreds of dollars to buy a new phone."

Sadly, he couldn't just switch back to a previous OS: Apple doesn't allow users to downgrade to an older version of iOS after installing the latest version. (There are ways around this, but it's a technical hassle for the average person.)

Apple is the only major smartphone company that keeps its older devices up to date with the latest versions of its mobile operating system. Samsung, HTC, Motorola, LG, and others tend to abandon major software updates after a year or two.

craig federighi ios 9 Apple SVP Craig Federighi announcing iOS 9 in June. Justin Sullivan/Getty Images

But it's a double-edged sword: Even though older Apple devices are able to run the latest software, some of the features have to be stripped down in order to run on the older hardware.

iOS 9 promised to fix that since it was designed to work on each device, which this lawsuit claims was misleading (or outright false).

Tech Insider has reached out to Apple and the law firm Bronstein, Gewirtz & Grossman, the law firm that filed the lawsuit, and we'll update this story if we hear back. It's unclear if anyone can still join the suit, but the law firm's website encourages visitors to join several others.

Here's a full look at the lawsuit, which was uploaded by Apple Insider:

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