For all other locations, such as installations in the United States and overseas, "the heads of DoD components will consider the inherent risks associated with geolocation capabilities on devices, applications, and services, both non-government and government-issued, by personnel both on and off duty", the memo states.
"These geolocation capabilities can expose personal information, locations, routines, and numbers of DoD personnel, and potentially create unintended security consequences and increased risk to the joint force and mission", says Shanahan's memo, which was released by the Pentagon press office too ensure everyone sees it.
The memo said Defense Department personnel were prohibited from using "geolocation features and functionality on government and non-government-issued devices, applications, and services while in locations designated as operational areas".
Military leaders will be able to conduct risk assessments to determine whether troops under their command can use the devices in the area or on the base they are located.
"The rapidly evolving market of devices, applications, and services with geolocation capabilities presents significant risk to Department of Defense (DoD) personnel both on and off duty, and to our military operations globally", the memo states".
Defense personnel who aren't in sensitive areas will be able to use Global Positioning System applications if their commanders conclude it doesn't pose a risk.
For example, troops exercising at major military bases around the country, such at Fort Hood in Texas or Norfolk Naval Station in Virginia, would likely be able to use the location software on their phones or fitness devices. Audricia Harris told reporters that it was a blanket restriction on the devices at locations deemed as an "operational area", which could include ships out at sea, classified bases or warzones or hostile locations in Syria, Iraq, Afghanistan or parts of Africa.
The Pentagon announced Monday that it is putting new restrictions on US troops carrying electronics, following revelations early this year that information they were sharing online could be collated to determine the locations of USA bases and units overseas.
And social network app company Strava in November published a heat map that showed the running routes of tens of millions of people using the technology. And while heavily populated areas were well lit, war zones such as Iraq and Syria showed scattered pockets of activity that could denote military or government personnel using fitness trackers as they move around.
While the ban will affect the U.S. overseas operations, the personnel working at the Pentagon will still be allowed to use the devices.
That memo called for stricter adherence to long-held practices that require phones be left in storage containers outside secure areas where sensitive matters are discussed. Officials say that information can present enemies with information on military operations.