Cyber Culture: Got this rare used MP3, mate. Yours for £50

Second-hand shops have that musty, backstreet magic, with dog-eared albums and well-thumbed books with the owner's name scrawled on the flyleaf. The goods have such character because they're inherently fragile; they're worn, almost in the process of falling apart. That's why the prices are so reasonable.

But the indestructible CD saw the record industry's attitude to second-hand sales start to wobble. With used CDs being of equal audio quality to new ones, why would the consumer bother buying the shrink-wrapped version? So when digital media came along, second-hand markets were obliterated with screeds of terms and conditions overriding the "first-sale doctrine" (our right to do whatever we like with things we've bought). When we pay for MP3s and e-books, we just get a licence; it's permission, not property. We're not allowed to sell them on for a knock-down price, because it would compromise the market for the originals.

But this is changing. At the end of last month, Amazon was granted a patent in the "secondary market for digital goods" that it filed back in 2009. It's clear that Amazon has ambitions to make money from unwanted digital files in much the same way as it does from used goods via Amazon Marketplace. You can already lend some Kindle e-book purchases to a friend (at which point it neatly disappears from your e-reader) and you can imagine a second-hand market working in a similar way, with your purchase vanishing from your device and popping up in an online store. Amazon then maintains control over the market by creating a fake scarcity; an OMT (Object Move Threshold) is mentioned in the patent, allowing a "used" MP3 or e-book to be sold once, but only once.

Last weekend, there were reports that the next Xbox console will block second-hand gaming, thanks to activation codes that tether them to the initial user's account. And any attempts by start-ups to create second-hand markets inevitably put them in the legal crosshairs. Last year, a company called ReDigi set up a second-hand store, coupled with a cloud-based transfer mechanism to move MP3s from one owner to another without actually copying them. It also initiated an artist-syndication scheme, rewarding creators for sales. Perhaps predictably, lawsuits flew; Capitol Records demanded a fine of £95,000 for every track that ReDigi sold, and that court case rumbles on, with arguments over whether an MP3 can be considered a "material object".

ReDigi continues to trade, and its founders describe the secondary market as "the future of the digital space". But with Amazon's patent awarded, that may be a market entirely controlled by one colossal internet corporation. And there's nothing charmingly musty or backstreet about that.

This embarrassing picture of me will self-destruct in 10, nine, eight…

Last year in a technology supplement with this paper, I mentioned in passing an app called Snapchat, a picture-messaging service that comes with a self-destruct mechanism; anything you send is visible to the recipient for between only two and 10 seconds (you decide) before vanishing into the ether. Despite a Snapchat founder insisting that "you can't build a business off sexting", the consequence-free exchange of naughty pictures seemed to be its only use, and I pondered whether it would sit ignored in the App Store. Well, the past few weeks have seen it zoom up the iOS and Android charts, the company has netted £9m in funding, Facebook has launched a copycat rival called Poke, and Snapchat itself now processes a reported 60 million messages every day.

It's hard to believe that all those messages consist of lewd content – how do people find the time? – so it's possible that Snapchat has additional appeal based upon its simplicity; conversations are fleeting and don't hang around on the internet or on your device, contrary to nearly every other messaging system in operation. But recent coverage of Snapchat continues to put nudity centre stage: do the naughty messages really disappear without trace? Does Snapchat make sexting safe? The answer is "not entirely", thanks to the ability of many phones to take screengrabs; it requires speed and dexterity to grab a Snapchat picture, but it can be done. The only weapon Snapchat has against screengrabs is to inform the sender when a recipient has done it – by which point it's too late anyway. So perhaps it's better not to send revealing snaps to strangers after all…

Lying politicians watch out, a live fact-checking app is listening to what you say

In an early episode of The Thick of It, Dosac minister Hugh Abbot watches a video of a speech he's given alongside a "worm" – a real-time indicator of how that speech is going down with the audience. A couple of weeks ago, The Washington Post launched "Truth Teller", an automated system that would make Hugh Abbot turn white with fear; it transcribes political speeches in real time, checks facts against databases and displays "TRUE" or "FALSE" alongside the video. Essentially, it's a political lie detector. The Washington Post's Steven Ginsberg had the idea after watching Michele Bachmann spout incorrect facts during her failed bid to become the Republican Party's presidential candidate, and it's certainly the case that lies can lead to voters making incorrect choices.

But political argument and debate can be elastic, and automated systems can be prone to error. You can certainly imagine Malcolm Tucker's response to a computer doubting the word of his minister – but I'll refrain from using such language in The Independent.

Android or Apple? Apple or Android? Finally a way to say which is better

The world of technology adores its platform wars, where users of one system denounce competing systems and refer to anyone who dares to disagree with them as a blithering arsenugget, or worse. The inexorable rise in smartphone and tablet usage has probably established the platform war of this decade as iOS (Apple) versus Android (Google) – and in terms of sales, it's one that Android is winning effortlessly. In the third quarter of 2012, Android shipments accounted for 75 per cent of the worldwide market, with iOS in second with a 14.9 per cent share.

Sales aren't everything, of course; the question of which of the two systems is actually the better is hotly debated. But a company called uTest has developed an application, Applause, that compares the quality of apps in the two stores – Google Play and iTunes – by mining user reviews and ratings. The stores have a similar number of apps (800,000 each, though Google's is rising much faster) but iOS apps are (he said, tentatively) generally considered to be of higher quality. Firstly because of the stringent controls imposed by Apple over submissions to its store, and also because the fragmented nature of the Android ecosystem makes it tricky to guarantee performance over a huge variety of devices. Applause backs up this hunch: the mean score for apps on iTunes comes in at 68.53, with Google's trailing at 63.34.

Of course, you could argue that basing a metric on ratings from the angry or biased users of app stores is ludicrous, and that the data from Applause can't be trusted – but hey. That's part and parcel of the platform war.