I met a PhD student working on digital forensics. He showed me how easily he could hack into any type of phone and how hard he is trying to protect his own digital information. He also told me know how he used these professional social networks in his daily life, for he believed that HRs are using the information on these websites to get some information about you before the interview, instead of your CV and recommendation letter. Maybe in the near future, it is a must. But at present, I feel to update it and keep an eye on it is not so easy for me.