Question: who rejected secret service protection after leaving the presidency
[{'answer': 'Richard Nixon', 'provenance': [{'wikipedia_id': '16335910', 'title': 'Former Presidents Act', 'start_paragraph_id': 18, 'start_character': 0, 'end_paragraph_id': 18, 'end_character': 13, 'bleu_score': 1.0, 'section': 'Section::::Current status.:Secret Service protection.\n'}]}, {'provenance': [{'wikipedia_id': '16335910', 'title': 'Former Presidents Act', 'start_paragraph_id': 18, 'start_character': 0, 'end_paragraph_id': 18, 'end_character': 93, 'bleu_score': 0.8702397637697911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1081972462238403450}, 'section': 'Section::::Current status.:Secret Service protection.\n'}]}]