I think report clearly says donation and extortion. The donation is definitely voluntarily from the local people. Taliban can not force local tribes, businesses or drug lords to give them money. Had this being situation, perhaps Taliban would have short lived. More over jazia from Sikhs not only voluntarily but may somewhat involved Indian intelligence to supplement the money. Read again.
*According to him, many politicians, businessmen, drug barons and jewellers in Kohat, Hangu, Thall, Kurram Agency, Darra Adamkhel and Bannu have been making periodic payments to the Taliban. *
*“So these donations are in addition to the money routinely and regularly extorted by the militants.” *
Taliban reportedly collect Rs15 million every year as “jazia” from the Sikh community in Orakzai Agency. They have also amassed huge sums through kidnapping for ransom.