It's not the creepiness that's relevant here. That's rather subjective, and as others have pointed out, all social networks do the same. What's most relevant h

It's not the creepiness that's relevant here. That's rather subjective, and as others have pointed out, all social networks do the same. What's most relevant here is that it's downright illegal in most Western countries LinkedIn e.a. operate in. Both collecting this information and sharing it without explicit (as in: not just default checked boxes) informed (as in: information about why, what and shared with whom) consent is not just unethical, it's a violation of most known privacy laws. The widespread practice of blatantly unethical business practices in our industry by both high profile companies and small start-ups alike is something we as professionals should take more seriously. If we don't, it doesn't only harm the image of our industry, but we'll be faced with ever more regulatory hurdles. The infamous EU cookie law is just the beginning if we don't act to clean up our own industry. Every second web company seems to have a business model that directly or indirectly generates revenue through stalking people on a massive scale. This cannot possible be sustainable without a huge backlash.