Alessandro Acquisti: Why privacy matters

Summery 
           With the processing of technology, we post lots of information online. But, we are not aware of the effect of doing this. Alessandro Acquisti did some experiments to tell us how far the big data can do to our privacy and explain how they effect our lives. First of all, he randomly found a student in campus and took a photo of him.Then, he use the face identity system used by facebook and found the student's profile on facebook. Based on this information, 27% of subjects's first 5 digit of SSN can be found (in 4 attempts).It is like when you walk on the street people around you can know some information about you without asking.So, does that mean we can know a person better? Not exactly.The photos and information we posted are partly.People would judge us according to what we post.That would generate biases.
           Subconsciously,we know this fact. Alessandro Acquisti did another experiment and demonstrated that people are familiar with the situation without privacy.It doesn't mean they don't care. They just can do nothing about this.Current policy is not effective.However,Alessandro Acquisti still believe we will find  solutions to protect our privacy and enjoy the benefit of big data in the same time.
     
What can listener learn from this talk?
                We can know the data online is really big. We never know who will use this information to do what things.What is more,the process of  technology has been so fast that everything becomes possible. We should always be aware of what we post on line!