http://abcnews.go.com/Business/trump-campaign-apps-data-grab-expose-contact-list/story?id=41642049..Trump’s app goes a step further by collecting information about other individuals through app users’ contact books.

“Trump’s is asking to collect significantly more data, and not just data about you, but data about anyone who might be in your contact list,” Nicole Ozer, technology and civil liberties policy director at the ACLU of Northern California, told ABC News.

Marc Rotenberg, executive director of the Electronic Privacy Information Center, said that Trump is "basically saying he has the right to pull down the contact list of the donors and supporters [using the app], which is something that is really very controversial."

Craig Spiezle of the Online Trust Alliance agreed, saying the policy was “very problematic,” and “not one that privacy or consumer advocates would consider reasonable.”

Collecting data from app users is not unique to the Trump campaign. However, Rotenberg said that the scope of the Republican nominee’s collection “in particular is egregious."

Of particular concern is the personal nature of data contained in modern electronic address books, which is often shared with personal confidants under the assumption that it will be kept private or shared with only the utmost discretion.

Address books on mobile phones don’t just contain phone numbers and email addresses -- which themselves may be private or sensitive. In many cases, they can contain notes about health information, snippets of emails, codes for security systems or garage doors, shared passwords, or even Social Security numbers.

Many people using apps that collect contact data, such as the Trump app, may not realize the extent of the information that they’re handing over, experts said....

The crucial decision is made during the initial registration process when the app is first launched.

Users are presented with a screen featuring the campaign logo superimposed over a photo of Trump. Beneath it they are presented with multiple options for registering an account with the app.

Further down still, in small text at the bottom of the screen, is a link to the app’s privacy policy, which, when clicked, takes users to the legal document on the campaign’s website.

During the registration process, ABC News journalists testing the app were presented with a pop-up screen requesting access to their address book. They denied the request and the app functioned normally during brief usage.

However, experts noted that privacy policies go partially or fully unread, and users often rapidly and impatiently click through pop-ups asking for permission to access the data. Some may not even know what a privacy policy is or that one is available, the experts noted.

A Pew Research study from late 2014 found that less than half of Americans polled correctly identified what a privacy policy is.

So, in many cases, users are unaware of what they’re about to hand over, experts said....