That's the philosophy behind some writers, they will only write what they know. The thing about writing the kinds of thrillers I want to write is there is a lot of police/political/legal research that goes into the plots. In fact the research takes so long that it's probably best to make up the technicalities, if need be, and just keep on writing. But some writers just prefer to write what they know, and stay away from researching or making things up. So is it a good idea, to only limiting yourself to what you know, or is it better to just not let realism bother you and make up technicalities to serve the story, if need be?