Database: legislator
Question: List the official full names of all the legislators who have facebook, instagram, twitter and youtube accounts.
SQL: SELECT T1.official_full_name FROM current AS T1 INNER JOIN `social-media` AS T2 ON T1.bioguide_id = T2.bioguide WHERE T2.facebook IS NOT NULL AND T2.instagram IS NOT NULL AND T2.twitter IS NOT NULL AND T2.youtube IS NOT NULL