The data collection, which took place over three years, was legal because the information was not encrypted, the F.C.C. ultimately determined.
Interesting how this works. If I went wardriving and collected personal emails from unencrypted networks, I'd have my house rummaged by FBI agents, be hit with a 25,000-count felony wiretapping indictment and have some go-getter federal prosecutor try to convince a judge to sentence me to 7,000 years in prison. Then an appeals court might say reverse on the grounds that it was unencrypted. Maybe.
Google does it? A slap on the wrist and a small fine for "obstructing an investigation."