HighlightsGoogle banned hundreds of apps for using ultrasonic beacons to collect user infoResearchers have found almost 234 Android applications were using this method.Applications were using this method to know user&rsquo;s location and interestsApps used the information to create personalized ads for the userSmartphones have become an integral part of our life our daily routines revolve around our phones. Mobile applications are now the best assistance that we have to act or perform almost every activity. We are so much indulged in the digital technology that we don&#39;t have any clue this much of interaction could be dangerous to us.Google just have band hundreds of apps from the Google Play Store as they were secretly spying by using the ultrasonic sounds without the user knowledge. This type of practice is prohibited by the Google and it doesn&#39;t come under privacy policies.Google has taken the step after research have revealed that hundreds of Android apps are using the ultrasonic cross-device tracking technology to collect the inaudible &ldquo;beacons&rdquo; that is emitted out by the advertisements. Applications draw the information like location and interests of the user with this technology to create user-oriented ads.This way applications were tracking the user activity and interest by gathering the information like what are they watching and engaging in. This helps them to design personalized ad and alerts to get their interest in the apps. This is the best marketing technique but with the wrong way. Using the microphone for catching beacon signals via user&#39;s mobile is considered as a threat to the user privacy and intolerable by the Google.Researchers have proven that almost 234 Android apps are using the technique of ultrasonic cross-device tracking to enhance their business. These apps were secretly spying on the user and hearing the background sounds like TV ads and others.Now Google has either banned the apps doing these or ask the makers to update them to meet private policies set by the company.We have seen recently breaching the user privacy is becoming a major concern in mobile app world. Apple has also found some of its apps using unnecessary or banned methods to gather user private information. These types of practices should be stopped by the app creators as users are losing their faith in the applications. Not only small but giant apps like Uber have been accused of taking inappropriate ways of saving their business.