1. I see a friend read an article that looks interesting. I click it.
2. Every time I click one of these I'm asked to add the application before I'm allowed to view the link.
3. My options are "ok" and "cancel". The first few times I assumed I couldn't read the article without clicking ok so I just hit the back button. It turns out "cancel" really means "don't add the app, just take me to the link".
Without that confirmation dialog (which most people probably blindly click through) this is exactly how social media worms work.
Perhaps alert users will click "cancel" the first 5 or 10 times, but eventually they're going to accidentally click "ok" or just give in. Not cool.
Plus, why would I want to see articles that friends read, but didn't think were worthy of manually posting about in the first place?