1) A common UX pattern to detect relevant clipboard links in the app (e.g. open a reddit link automatically) -- many apps do this type of thing (e.g. Photoshop will use the dimensions of a clipboard image when creating a new image), but nobody's pointed out specific such functionality in LinkedIn (or reddit)
2) A third-party library (analytics, advertising) which does this automatically, which the app developers (LinkedIn, Reddit, etc.) weren't even aware of. If so, why though -- is there some particular analytics, tracking or fingerprinting reason? I'm having a hard time thinking of any particularly good one
3) Something else, like a common text editor library that checks the clipboard by default for some legitimate reason like preparing for formatting, images, etc., that is maybe just lazily coded (checking clipboard on every keystroke, rather than just a paste command)
I'm just curious if anyone has facts. Because there's a world of difference between good intent, questionable intent, bad intent, and lazy intent.