Michele Bachmann gets security detail after IS threat. How do other representatives protect themselves?

In a rare step, Rep. Michele Bachmann, (R) of Minnesota, has been assigned her own security detail after receiving an online threat claiming to be from the Islamic State (IS), Politico reported Monday. 

Bachmann has been a vocal critic of President Obama's policies toward the Islamic State and in September argued that Islam itself lay at the root of the terrorist group, MSNBC reported. She also introduced legislation that would remove Americans' citizenship if they joined IS. 

Ordinarily, representatives receive 24-hour protection when they're in the Capitol building but not when they're in their home district. The only members of Congress to have an assigned security detail are members of the House and Senate leadership, such as the House Speaker and Senate majority leader. Ordinary representatives do not receive such protection unless there is cause for concern, according to The Hill.

It is highly unusual for ordinary members of Congress to receive special protection outside of Washington, according to Mark Strand, president of the nonprofit Congressional Institute. He says that because members receive large numbers of threats, when a member does receive added security, it is because the Capitol Police are taking the threat seriously. 

"If they decided that this was needed then they have some good reason for it," Mr. Strand says of Bachmann's security detail. While he says this type of extra a protection has been offered to members of Congress in the past, he says it is difficult to know when it has happened and for whom because Capitol Police do not announce added protection for congressional members.

A Capitol Police spokesman did not respond to requests seeking comment. 

While attacks on the Capitol building are rare, they have occurred. In July 1998, a gunman made his way into the Capitol building, leaving two police officers dead. Following the Sept. 11 terrorist attacks, two senators received letters containing anthrax.

And in the most serious recent example of violence against a sitting congresswoman, former Rep. Gabrielle Giffords, (D) of Arizona, was shot in Tucson, Ariz. in 2011 while meeting with her constituents. 

Threats are a more common occurrence. For example, during the contentious 2010 debate over health-care reform, several House members received threats, The Hill reports. 

And last year, Rep. Carolyn Maloney, (D) of New York, said she received death threats at her Manhattan office following her introduction of a bill to require weapon owners to have liability insurance. 

Over the years, different members of Congress have been known to take their own security measures. Some, such as former Rep. Heath Shuler (D) of North Carolina, said they carry concealed weapons when in their home district. Others, such as former Rep. Patrick Kennedy (D) of Rhode Island, said they work with local law enforcement in their district to coordinate safety plans, particularly for public events, according to The Hill.