It wasn’t a huge one in terms of time or resources, but back when cellphones were new and only rich people had them, Spain’s Traffic policemen were very keen on banning their use while driving. Politicians (a group likely to have cellphones, at the time) didn’t see what the problem was - until the signal from one of them was intercepted by some reporters during a conversation in which he called many of his colleagues (mainly from his own party) by very unflattering nicknames.
That wasn’t any kind of crime, or felony, or whatever beyond a faux pas, except the cops got a recording off a TV broadcast of the tape and used this recording to get a judge’s permission to gain access to the original tapes. Which they then analyzed for Doppler effect, slamming the politician with what at that point was one of the highest speeding tickets on record.
Amazingly enough, Parliament passed a law banning cellphone use while driving as quickly as they were able to write it.