I do think it is a valid concern. Over the years, various sources reported that intelligence agencies mostly use metadata (who's talking to whom, i.e. the social network) in their analysis because message content is harder to parse and understand (and, outside of email traffic, harder to obtain in the first place).
Metadata can be as damning as the actual message data, and in a lot of places you don't want the authorities to know that you are even communicating at all.
