It is assumed that young people simply "know" how to use technology well. While it is true that children are growing up with the technology, most are unaware of how to use it effectively. A perfect analogy is the book. A kid who has grown up reading fantasy does not automatically know how to use a text book.
Students need to be shown how to identify and use appropriate technology. One of the most basic skills is how to search for valid information online. One study found that students trust Google to tell them which sites are most trustworthy rather than depending on their own judgement. With the internet generating astronomical amounts of media, students face an increasing threat of deception.
There are some simple things that we can do as teachers. We can regularly ask students to consider the source of any information they get. We can ask students to question what they are told (even when it comes from us). Perhaps the most important thing we can do is to regularly insist on analysis. Of course this is just good all around teaching. In our new online world though, this takes on new importance. When students get in the habit of thinking about what they are told, they will be less likely to be swayed what they see online.