Urban Grimoire: A Modern Spell for Use with Large Corporations

I have had two interesting experiences recently of using a modern spell - literally words to make a change.
Usually I'm not terribly taken with online reviews  because usually they are too easily manipulated, but I have seen how leaving an online review can genuinely impact on a large company's reputation 
Regular readers will remember my shitty previous employers. I left a simply terrible review on a well-known recruitment website for them. At the time I left my review all the others were glowing, so mine was the odd one out, and could have been seen as someone with an axe to grind. I have recently gone back to the site and found that my review has given other people the courage to leave bad reviews, and so now anyone going on that site sees that they are a terrible employer. The lesson I suppose is that one person's courage in the face of bullies encourages others to speak out.
I also left a poor review for the local office of the large national company which 'manages' the building I live in. (I have long accepted that my lot in life is to be the one who points out that somebody is being a turd, it isn't solely that I'm a miserable bastard. True to form, other poor reviews have followed, and I was amused to see on a large review website that my review, while bad, wasn't even the worst because someone had already left a review calling them criminals!
It just goes to show that speaking something brings it into being.