Via Volokh, parents in Illinois are suing to establish a moratorium on the use of WiFi in classrooms, fearing that the low-level radiation may harm kids. The concern isn't totally irrational, but there's no solid evidence that this is the case either. But plenty of businesses (like the cafe from which I'm writing this post) which make free WiFi available to attract customers may decide it's not worth risking lawsuits, whether or not the fears are sound.