True, but there's a lot of people out there that have genuine knowledge about whatever the subject is, and if you wait a few days usually you'll be able to find multiple sources to verify or dismiss any claim.
The main problem is how much time and effort one is willing to invest into debunking the fake news stories? For the most of people answer is: not any, if possible. Even I will look at maybe 2-3 pages of google results and twitter feeds and give up, presume it's true. It's the same problem as computer security: it's all about the balance between the goal and convenience. It's just not convenient to double-check every fact that you read, you'd just do that whole day long or go crazy, so we choose to trust them...
The main problem is how much time and effort one is willing to invest into debunking the fake news stories? For the most of people answer is: not any, if possible. Even I will look at maybe 2-3 pages of google results and twitter feeds and give up, presume it's true. It's the same problem as computer security: it's all about the balance between the goal and convenience. It's just not convenient to double-check every fact that you read, you'd just do that whole day long or go crazy, so we choose to trust them...