Free/Libre and Open Source advantage
I made an Android app that reads the clipboard on startup without asking. It does it to see if the clipboard contents is a URL, in which case it pre-populates a text field with that URL. I could have added an extra Paste button, but then I'd have to worry about issues like "would the button take up too much room on small displays" (or if it's hidden, would users be able to find it), and "would users be confused if pressing the button causes an error message because the clipboard contents is not something we can handle—would it be better to simply not offer the option in that case". So I decided (rightly or wrongly) that reading the clipboard without asking would be the least-bad thing to do by default.
But my app is Free/Libre and Open Source Software. If you don't trust me, you can read the source code (or trust that others will have read it and called me out already if necessary). To make really sure, you can compile it yourself and verify that the bytecode you get is the same as the bytecode on the Play Store version (if you use the exact same compiler version and options as I did).
Unfortunately for LinkedIn, they have so far not been brave enough to show the source code of their app, so it's not as easy for them to use the "just read the code" defence. (Perhaps they'll now invite lawyers to look at it behind closed doors, but publishing it could have saved that trouble.) LinkedIn has open-sourced some minor components, but not the app itself. I don't know the business reasons for that decision, but it seems clear to have this PR disadvantage at least.
That said, the iOS ecosystem itself isn't exactly helping. It doesn't make it at all easy to verify that what you get from the App Store is the same as what you can compile from source code, plus its incompatibility with certain licenses (along with the general high financial cost of being an Apple developer) seems to have resulted in an environment somewhat devoid of Free/Libre and Open Source Software (so iOS users are missing out on some of the best software). But in LinkedIn's case I have not been able to find their published source code for the Android app either, sorry to say.