@Dennis, look at it from the deterrence point of view. If the state abdicated on its roles, what little contribution can you make? I may not succeed in bringing the bad guys to book, but I may just discourage the vice.

CCTVs have been there since when pluto was a planet, but should their use be inadmissible to authorities, you can leverage on their less costly alternatives and twist their use into interesting initiatives especially on emerging media - 'crowd-sourcing deterrence'.

When you are an afflicted party, any form of evidence is good evidence. It builds up on your claims apart from offering some psychological score of having done your part. Ask that guy who's chasing some payment for services offered about his sentiments on evidence to prop up his case. (BTW, if he's reading this, in legal circles, there's a tool that looks handy on paper : "Demand Letter" )

Samples :

Remember Charles Kungu and his office laptop theft case? What if you happened to recognize the culprit in the video.
Then there was also the case of a gang of lady thieves who eventually got caught.
A personal favourite is the case of Makena Onjerika on MPESA fraud. (She even went on to start an active facebook group)
Some people swear by the buyer beware facebook group

You just never know what impact social groupings like KOT may come in handy.

Tony