Is it ok for companies to look through the applicants social media profiles during the hiring process??
This is just my opinion and a separate issue from companies requiring applicants to turn over user names and passwords.
IF an applicant's social media is set to public a company looking through the applicant's social media posts and profiles is fair game. However, if the applicant has the social media accounts set to private then in my opinion it is wrong because the company would have to do something invasive and violate the applicant's privacy in order to view the social media accounts.
If the applicant at one time had the social media accounts public but set the accounts to private later the only acceptable way a company could look through the applicant's accounts in my opinion would be through a legitimate archive that is available to the public.
Therefore, in general as long as an applicant's privacy isn't being infringed on and the company is acting morally I have no problem with a company reviewing an applicant's social media accounts. There are legitimate reasons for doing that and I would probably do it if I were an employer.