The media essentially created the cell phone scare when CNN's Larry King Live hosted widower David Reynard in 1993. Reynard was suing several phone companies because his wife, who used a cell phone, died of a brain tumor. Reynard and his lawyer didn't have much of what you might call evidence, which is why they didn't get very far in the courts. But the issue has hung around as a media fascination. Television shows and news reports can, in a matter of moments, leave a lasting impression.
Science is different.
It takes years to collect and analyze data, and that's just for one study. To really establish a theory, it needs to hold up through numerous studies by different scientists. The results must be replicable and verifiable, confirmed again and again by people running similar experiments. Over time, the studies get more refined. For example, some research has indicated that cell phone users are healthier than the rest of us.