Might sound a bit antagonistic (not meant to be) but are you sure that's productive?
Imagine the conversation - "you were videoed by a cyclist using a phone" sure, it might get them to stop using a phone in their van, but not necessarily in their cars, and will probably antagonise them to cyclists. Regardless of the potential danger of using a phone, I'd rather have that than actual danger resulting from bad, inconsiderate or downright dangerous driving.
I'd disagree with that - the more any driver is made to think about their actions, the better. The last company employee I spotted seeing on the phone, worked for Beds Fire & Rescue Service in their education team. After sending off a complaint letter, I got a very apologetic reply back confirming that the person had been reprimanded and the entire team had been sent on a training course highlighting the errors of mobile phone use whilst driving.
Whilst I've no doubt it annoyed the woman being caught out, the more it happens, the better, and if she moans about it to her friends, it might just make some of them think about the consequences as well.
As a suggestion, if you want to have an impact on phone use you could stand by the roadside at almost any busy junction, inside half an hour you will have videoed probably 15 (?) commercial drivers using phones and the complaint would then come from a pedestrian. I've seriously thought of doing this.
Good point, although when I do complain about people, I tend not to state if I was walking, driving or cycling as it's not really relevant. Standing and videoing drivers on their phones is something I've thought about doing as well. With a captive audience in the London rush hour, you'd get quite a few. Perhaps we ought to think about a regular stakeout.