This is why apps such as Instagram have been banned in places like mainland China during the Hong Kong protests, and why apps such as FireChat have seen an increase in use during such events. However it seems that authorities are catching on quick to the potential that such apps have and over in Bangladesh, the government has placed a temporary ban on apps such as Viber and Tango.
Local law enforcement agencies have ordered that The Bangladesh Telecommunications and Regulatory Commission shut down both services and prevent them from being operated in the country. While the exact reason was not given, it has been speculated that the ban on these services is to prevent anti-government protesters from communicating with each other freely.
As it stands, there are activists from the Bangladesh Nationalist Party who together with their allies and trying to overthrow the current government. However it seems that the ban on these services appear to be temporary although there is no word on when either service will be allowed to continue operating in the country.