Bottom line: Apple's revised stance isn't so much about keeping consenting individuals from doing what they want with their hardware but rather, protecting unsuspecting users from scammers looking to hijack processing power for personal gain.
Apple is taking a stand against the mining of cryptocurrencies on its devices. Changes to the App Store Review Guidelines, recently spotted by Apple Insider, highlight Cupertino's revised position as it relates to virtual currency creation through App Store apps.
In section 2.4.2 under the Hardware Compatibility category, Apple says apps, including any third-party advertisements displayed in them, may not run unrelated background processes such as cryptocurrency mining.
Previous iterations of this rule found via the Wayback Machine only state that developers should design apps to use power efficiently by avoiding those that rapidly drain battery, generate excessive heat or put unnecessary strain on device resources.
An expanded section - 3.1.5 (b) - specifically dealing with cryptocurrencies outlines the following five guidelines:
- (i) Wallets: Apps may facilitate virtual currency storage, provided they are offered by developers enrolled as an organization.
- (ii) Mining: Apps may not mine for cryptocurrencies unless the processing is performed off device (e.g. cloud-based mining).
- (iii) Exchanges: Apps may facilitate transactions or transmissions of cryptocurrency on an approved exchange, provided they are offered by the exchange itself.
- (iv) Initial Coin Offerings: Apps facilitating Initial Coin Offerings ("ICOs"), cryptocurrency futures trading, and other crypto-securities or quasi-securities trading must come from established banks, securities firms, futures commission merchants ("FCM"), or other approved financial institutions and must comply with all applicable law.
- (v) Cryptocurrency apps may not offer currency for completing tasks, such as downloading other apps, encouraging other users to download, posting to social networks, etc.
In short, Apple isn't outright banning the presence or usage of cryptocurrencies on its devices but it doesn't want you creating them with their products. Determined users will still be able to mine for cryptocurrency on jailbroken devices and on the Mac outside of Apple's walled garden although in most cases, mining on such devices is far from economically feasible and only employed by nefarious parties to do so at the expense of others.