I agree - an attorney if you can afford it, and the media for sure. That stinks! The garbage can idea sounds more pleasant than drowning, although you're goign to have a frantic cat or two in your garbage can until the CO2 kicks in. You're going to have to do something.
RichnSteph - I'm thinking of your grandma's garden. It's so sad that she can't garden anymore. At this point, I don't even know that it would be healthy for her to do so with all that's in the soil from the waste of all those cats...
She may be able to find an attorney who's willing to take this case pro bono. It would be well worth looking into.