I just heard this podcast that I thought might be a good thing to use during this time of the year. It touches on global impact in a big way AND encoding of data (a 2-4-1)!
In the podcast, they talk about how images and sound can be manipulated and what types of ramifications that has for society. They also features several computer scientists who talk about their concern (or lack there of) for the possible harm this may cause. I think it could spark good conversations between students and be relevant for this unit.
BE WARNED though, there is a bit of a political leaning here - they do play some of the more un-presidential quotes from our current president so I could understand that some teachers might be wary of phone calls they might get about assigning it. You could always assign just part of the podcast too or listen to part of it in class.