We've talked about app permissions on this newsletter before, largely because they are incredibly important when considering your own security posture, and also because apps are one of the primary avenues by which companies are able to harvest copious amounts of your data-- including precise location data, which allows companies to deliver personalized ads based on your geographical location. This is why you would see, for example, ads for local businesses, ads that are relevant to needs in your area, or political ads paid for specifically for people in your ZIP code. This is a legitimately useful service; as personalized ads might show you something that could actually be useful. However, there is little oversight for companies that are harvesting and storing this data, and their practices are often indiscriminate of who they collect from and borderline unethical on how that data is stored, shared, or sold off.
Outside of browsing the web on a computer, one of the primary methods for data collection is through the use of "free" apps on your phone or other devices, or even when just using a desktop program. These apps and programs often ask for specific permissions (and they often make a case to you for why they need these, like access to photos for sharing photos on Instagram, or location data for weather reporting). In these cases, it's fine-- especially if you specify that it can only have access when you are actively using the app. However, many of these apps pressure and prod you for extensive, unrestricted access, and when given that access, will send near real-time updates on your location and status to their home servers, and never make clear to their users exactly how much data will be collected.
These things are troubling for obvious reasons, but this article on Forbes gives us a better look at just how much data is being harvested, and what proportion of apps are asking for which permissions. It's pretty interesting to see, and should be a tool for informing how you use apps in the future!