Speaking at a technology conference organized by The Wall Street Journal in Laguna Beach, Calif., Apple CEO Tim Cook on Monday unveiled that more than 15 million users have used Apple Music service and also commented on the apps that have been removed from Apple's online store due to privacy concerns. Cook said that an additional 8.5 million people are participating in a free trial of the Apple Music service. That gives it more than 15 million users in total, which Cook described as a successful debut.

"I'm really happy about it, and I think the runway here is really good," Cook said.

Released in June, Apple Music is the company's attempt to carry its dominance of digital music through its iTunes store into the era of music streaming pioneered by Spotify and others. Apple is allowing users to test its service with a 90-day free trial, which elapsed for the first users earlier this month.

Rival Spotify, the industry leader, has more than 20 million paid subscribers worldwide.

Cook also touched on Apple TV, which recently received an update. A new version of the set-top box featuring apps and expanded search features will be released later this month, but the product does not include a streaming TV service, which industry executives say the company is exploring.

Updates include onboard storage, a new touchpad remote, tvOS and a dedicated app store as well as considerable Siri integration. Two models are available: 32GB ($149) and 64GB ($199).

Preordering for the new Apple TV will open on Monday.

Apple is also kicking out applications that collect personal data in violation of the company's privacy policies from its online store.

The iPhone maker made the announcement a day after researchers discovered hundreds of apps using Chinese advertising software that extracts "personally identifiable user information."

"We've identified a group of apps that are using a third-party advertising SDK (software development kit), developed by Youmi, a mobile advertising provider, that... gather private information, such as user email addresses and device identifiers, and route data to its company server," the California-based company said.

"This is a violation of our security and privacy guidelines. The apps using Youmi's SDK will be removed from the App Store and any new apps submitted to the App Store using this SDK will be rejected.

Apple does not allow third-party applications to share data about a user without obtaining users' permission, and it rejects apps that require users to share personal information, such as email addresses or birth dates.

Ragarding Apple's entry into the market of electric vehicles, Cook did not publicly acknowledge efforts by Apple to build an electric vehicle. But he sketched out his future vision of what cars will look like, with a greater infusion of technology.

"What I see is that software becomes an increasingly important component of the car of the future," he said. "You see that autonomous driving becomes much more important."