Use handheld devices like ones used by traffic police: HC
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/%E2%80%98collect-fines-spot-people-found-littering%E2%80%99
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/hindu-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/waste-management
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dengue
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/chikungunya
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/malaria
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/sunita-narain
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/solid-waste