It’s easy to make the case for a Kindle. It’s portable, you can read it in the dark, and it makes it dumb easy to download a book from Amazon almost instantaneously. But it’s still a device, standardized in a few different forms — the Oasis, the Paperwhite, and so on — lacking the personal touches you’d get in a book with that aged-paper smell, margin notes, dog-eared pages, whatever. A community of amateur and seasoned hackers have figured out how to tinker with Kindles to make the experience a little more “theirs,” reconfiguring them with unapproved fonts and bypassing the ads Amazon injects into cheaper versions of the e-reader.

Some of these hacks also bypass Amazon’s storefront and approved file formats. Users might load pirated .epub books onto their Kindle rather than buying Amazon’s proprietary .mobi format, thereby limiting the amount of data the company is able to collect on their habits.

Jessamyn West, a librarian and technologist in Vermont, says she was a pretty late adopter to the world of Kindles, but after a power outage left her unable to read one night, she was inspired to buy a refurbished backlit Kindle on eBay for about $50. West says she hated how her Kindle’s pages refreshed and went down a rabbit hole of Google searches to see if she could fix it. She ended up finding a community of Kindle hackers who had figured out how to do a bunch of stuff on the device she hadn’t thought of, like replacing Amazon’s stock wallpaper.

“I just don’t like looking at it,” West says of the default images that would appear when she turned the Kindle off. “It had nothing to do with my reading experience. I just didn’t want to look at it.”

“I’m not sitting at home with my Faraday cage, but I do think it’s worth being mindful that they are a gigantic corporation.”

West also saw certain hacks as a way to distance herself — and her reading activity — from Amazon. She figured out how to move different book formats, books from the library, and her own PDFs onto the device without having to go through Amazon, effectively finding alternatives to the tech giant’s ecosystem.

“I don’t want them to know what I’m reading,” says West, referring to Amazon. “I don’t want them to know how far I’ve read in a book.”

She says that because Kindles are connected to the internet, and because users are forced to transact with Amazon for new books, they hand over a wealth of data about users’ reading preferences and habits to the company.

“I’m not sitting at home with my Faraday cage, but I do think it’s worth being mindful that they are a gigantic corporation,” says West, adding that the company’s data collection gives it a competitive edge.

West points to AmazonBasics as an example. Because Amazon both owns the store and sells its own products, the company can easily spot the bestselling extension cord, buy extension cords in bulk from the manufacturer, and then undercut the other merchants offering that bestselling cord since it has market data that other companies don’t.

Tom Mercer, senior vice president of digital products for library e-book vendor Bibliotheca, called out Amazon in August for likely using this sort of competitive market data to convince authors and agents that libraries are bad for their sales, Publishers Weekly reported.

“Your e-book reader, if it isn’t hacked, can contribute to that,” West says. “Not that everyone’s complicit, obviously, but it’s worth understanding the ecosystem in which your reading is taking place.”

Amazon says it uses collected data to help users.

“Maintaining the trust of our customers by protecting their privacy and ensuring the security of their data is a longstanding top priority for Amazon,” an Amazon spokesperson said when asked about how the company tracks user habits, including what books they purchase, when they read, how far into a book they are, and what they take notes on or highlight. “Some information, like the details you mentioned, are logged in order to ensure the performance of our products and services and improve the customer experience.”

Of course, some people augment their Kindles for less idealistic reasons. Iman, a 33-year-old multimedia producer in Massachusetts, who asked not to use his last name to avoid identification in the hacking community, says that as someone who grew up reading physical books, he had gotten used to the ritual of putting his book on the nightstand when he went to bed and seeing the cover image when he woke up. He now has three Kindle devices, and since Amazon doesn’t let you set the wallpaper to whatever book you’re reading, he hacks them to do just that.

“It emulates that experience of reading,” Iman says. “Instead of the generic set of images that Amazon has on the Kindles, I wanted to have that book cover be the screensaver, so every time I’ve gotten a new Kindle, I’ve waited for the jailbreak to become available and installed it specifically for this hack.”

Now when he looks over to his nightstand, Iman sees the covers of Marie Kondo’s Spark Joy, J.R.R. Tolkien’s The Two Towers, or a collection of short stories from the fantasy card game Magic: The Gathering. In its way, this too can be a subtle act of resistance: Amazon offers slightly discounted Kindles that come with “special offers,” meaning they display advertisements when you’re not using them. Though you can disable these through a one-time payment to Amazon, some hackers circumvent the images through other means, replacing the stock wallpapers with their own.