Answer: Legal but unethical
Explanation: The course of actions that Carly takes are clearly legal but could not be considered ethical.
She is doing her research from the information that is publicly available on the accounts of applicants. Also she did not try to interfere with the personal details. Hence her work is legal.
However judging someone for a job on the basis of their social media accounts should not be considered ethical as the details provided are still their personal life details and should not be considered for judging them as professionals.