decade in hiding. our senior international correspondent stan grant investigates a very old and very shady way of exchanging cash in pakistan. reporter: branded terrorist banking. doesn t take long important people to get nervous. we are outside the uncomfortably named but unconnected osama money exchange. these meant don t want us here. we can t say we are hiding anything. according to those that know, you want to trace the black money trail, this is the time and place to start. this is the sort of place where these transactions are carried out. we can see this type of place, i told you. reporter: he s a pakistani academic who tracks the workings of al qaeda. he zeroed in on osama bin laden s financing. bankrolling, terror network, he says, tens of millions of dollars each year. how to do it? something called banking.
columbia. that s why we are reporting from outside. there are major developments involving cell phones, information that you need to know from the world health organization about the possible danger of cell phone use and cancer. stand by. elizabeth cohen has a full report. we re also watching bin laden and the black money trail. new information coming in on money and bin laden. stand by for that as well. we ll have the latest on anthony weiner, the congressman from new york. our own dana bash is following up on this story. i m wolf blitzer. you re in the situation room. but we begin with major developments involving cell phone use and you. information that you need to know right now. the world health organization for the first time has raised a serious possibility of a link between cell phone use and cancer. here s our report. what did this world health organization report conclude? the who concluded that cell phone are a possible carcinogen for humans. this is a really