"They could put in their own app-screening solution, so iOS scans the app package before even allowing it to install," says Creative Strategies CEO and principal analyst Ben Bajarin. "Some browsers do this—they won't even allow you to visit a website if they detect a malicious code." Riley Testut, a developer whose AltStore offers a way to sideload apps onto the iPhone, agrees.

Link: How your iPhone could change if the feds end Apple's App Store monopoly
via http://www.fastcompany.com