While its recent attack on a 14-year-old girl in Pakistan brought international outrage, the Pakistani Taliban take credit for a long list of assaults on civilians and the military in the country's mostly ungoverned tribal area along the Afghan border.
The banned Islamist group, which has intimate links to the Afghan Taliban and al Qaeda, unabashedly confirmed it tried to kill teen activist Malala Yousufzai as she rode home from school in a van October 9.
But before that, the group, formally known as Tehrik-i-Taliban Pakistan (TTP), took the global spotlight when Faisal Shahzad, a Pakistani-American, attempted to detonate a car bomb in New York's Times Square in May 2010. The TTP took responsibility, and Shahzad testified that he had received training from them.
The following September, the U.S. State Department designated the TTP a Foreign Terrorist Organization.
Are they "the Taliban?"
They are not "the Taliban" that the U.S. forces have been at war with in Afghanistan, according to a Pakistani analyst. But that they adopted the name "Taliban" is no coincidence.
Formally known as Tehrik-i-Taliban Pakistan, the group is very closely linked with its namesake in Afghanistan as well as with al Qaeda. It shares its religious extremist ideology -- but is its own distinct group.
The TTP also has a different goal, but its tactics are the same, says Raza Rumi, director of policy and programs at the Jinnah Institute, a Pakistani think tank.
"Their primary target is the Pakistani state and its military," he says. "It resents the fact that it (Pakistan) has an alliance with the West, and it wants Sharia to be imposed in Pakistan."
Another terrorism analyst notes that "there is a shared heritage between the two groups."
"The Pakistani Taliban emerged as a power alongside the Taliban as a kind of network of support," says Matthew Henman of IHS Jane's Terrorism and Insurgency Centre.
During the Soviet occupation of Afghanistan, fighters from Pakistan crossed over the border to fight. They retained close relations with the Taliban after returning home, Rumi says.
There are other militant groups in Pakistan's tribal region not under the umbrella of the TTP, who support the Taliban but do not pursue Tehrik-i-Taliban's goals of replacing the Pakistani state with an Islamist one.
Where do the TTP's roots lie?
Pakistan's army began hunting various militant groups in the semi-autonomous regions along Pakistan's border with Afghanistan, known as the Federally Administered Tribal Areas (FATA), in 2002.
In reaction, militant "supporters of the Afghan Taliban in the tribal areas transitioned into a mainstream Taliban force of their own," according to the Council on Foreign Relations.
In 2007, like-minded militias in Pakistan's tribal region came together under the command of Baitullah Mehsud, who was killed in a U.S. drone strike in 2009.
As a result of its beginnings, Tehrik-i-Taliban are not a unified fighting force but a coordinated coalition of militias.
"Since its formation, the TTP have been dominated by one tribe," Henman says. "That is the Mehsud tribe." When Baitullah Mehsud died, factions competed for Tehrik-i-Taliban's leadership.
The militant groups control different regions within the tribal area and often have different agendas and political objectives. The factions don't always speak with one voice, although it is widely believed they now recognize Hakimullah Mehsud as their leader.
The TTP may have started in the tribal regions, but have since expanded their network.
They are "not just guys hiding in mountains or caves." They maintain loose factions spread out as far as Punjab province, Rumi explains.
"And they have also been joined by criminal gangs" to raise money through kidnappings and extortion. But the TTP have maintained the coalition nature of their roots, which leads to internal strife.
The TTP's opposition to the government and its allies, particularly the United States, has galvanized them beyond their differences.
"When (former president Gen. Pervez) Musharraf sided with the U.S. in 2001 after the 'you are either with us or against us' line from (then-President George W.) Bush, this is when the Taliban began to resent the military," Rumi says.
The TTP do not encompass all militant groups in the tribal regions but does work together with some, such as the Haqqani Network.
What is the Pakistani Taliban's mission?
The TTP are fighting to overthrow Pakistan's government via a terrorist campaign, according to the U.S. State Department.
"They reject the Pakistani constitution," says Rumi. "They reject the democratic process in Pakistan."
Because of Pakistan's alliances with the United States and other countries, the Pakistani Taliban also attack foreign interests in and outside of Pakistan.
Within Pakistan, Tehrik-i-Taliban often target members of Pakistan's armed forces but also kill civilians for political and religious reasons. In a December 2009 bombing of a mosque frequented by Pakistani military personnel, the group killed 36 and wounded 75.
In March 2011, a TTP bomb planted at a natural gas station killed dozens.
An attack on a Sufi shrine in April 2011 killed more that 50 in Dera Ghazi Khan, said the U.S. State Department, which also suspects the group may have been involved in the killing of former Pakistani Prime Minister Benazir Bhutto in 2007.
Assaults on U.S. and other foreign interests have included attacks on a military base in Afghanistan and a U.S. Consulate in Peshawar. The TTP have also claimed responsibility for the assassination of a Saudi Arabian diplomat.
"Their ambitions are linked to the agenda of al Qaeda," says Rumi. They would like to bring down the West and the United States, but "given their capacity and network, they are overreaching."
Why the May 2010 Times Square bombing attempt?
Since the United States is not in a state of war with Pakistan, its military does not pursue the Pakistani Taliban within that country's borders.
Instead, the CIA has hammered the TTP and other targets in the tribal regions with drone strikes, which have inflicted heavy losses but not stamped it out.
The New York City bombing attempt has been interpreted by some as an act of revenge.
TTP leader Hakimullah Mehsud recorded an audio message in April 2010 with a warning to the United States: "From now on the main targets of our fedayeen (fighters) are American cities."