PHMSA is issuing this Advisory Bulletin in coordination with the Department of Homeland Security's (DHS), Transportation Security Administration (TSA), to remind all pipeline owners and operators of the importance of safeguarding and securing their pipeline facilities and monitoring their Supervisory Control and Data Acquisition (SCADA) systems for abnormal operations and/or indications of unauthorized access or interference with safe pipeline operations. Additionally, this Advisory Bulletin is to remind the public of the dangers associated with tampering with pipeline system facilities.This Advisory Bulletin follows recent incidents in the United States that highlight threats to oil and gas infrastructure. On October 11, 2016, several unauthorized persons accessed and interfered with pipeline operations in four states, creating the potential for serious infrastructure damage and significant economic and environmental harm, as well as endangering public safety. While the incidents did not result in any damage or injuries, the potential impacts emphasize the need for increased awareness and vigilance.