Give the name of the community area which had the most pocket-picking thefts.
name of the community area refers to community_area_name; the most refers to max(case_number); pocket-picking theft refers to primary_description = 'THEFT' AND secondary_description = 'POCKET-PICKING'
SELECT T3.community_area_name FROM IUCR AS T1 INNER JOIN Crime AS T2 ON T1.iucr_no = T2.iucr_no INNER JOIN Community_Area AS T3 ON T2.community_area_no = T3.community_area_no WHERE T1.primary_description = 'THEFT' AND T1.secondary_description = 'POCKET-PICKING' GROUP BY T2.community_area_no ORDER BY T2.case_number DESC LIMIT 1