How many Jewish legislators do not have facebook?
Jewish legislators refers to religion_bio = 'Jewish'; do not have facebook refers to facebook is null;
SELECT COUNT(T3.bioguide_id) FROM ( SELECT T1.bioguide_id FROM current AS T1 INNER JOIN `social-media` AS T2 ON T1.bioguide_id = T2.bioguide WHERE T2.facebook IS NULL GROUP BY T1.bioguide_id ) T3