Individual sites and people take advantage of the Apple Developer program to activate iPhones unofficially so that one can get early access to iOS beta versions. They charge users something between $2 to $20 depending on other features provided by them. Apple has always remained careful with such activations, but this time Apple is making sure to take down website offering this services more strictly.
Apple gives out early access to developers to test and report all the bugs in any iOS version. The developers need to purchase a developer account from Apple which cost at 99$/year for developer account. This is an essential for developers who develop apps, test apps and deploy apps into the app store. But lately some developers, private websites and individuals started taking advantage of this program and sell a service which will activate your iPhone for a minimal payment which is often much less than what Apple charges.
Each developer account has a limit of 100 device activations that can happen over the account. So imagine the kind of money they make by selling the device activation service. Even considering $5/device and 99$ activation fee paid to Apple each account can fetch around $400! A private website claims that it has made around $75000 only in the month of July by selling device activation service.
Apple is making sure to take down all the websites offering such service. It is also clearly mentioned on any Developer Account dashboard that their account might be permanently terminated if Apple feels that the account is violating Apple’s policy by selling device activation service.
Beta versions of iOS are meant for developers only and not general users. There might be many reasons for this, one main reason being many Apps crash on beta version as they are not made compatible to beta versions yet. Such users typically give a low rating to these Apps thus hurting the App developers.