I'm so sorry to hear what happened to the two girls. Certainly deeds like these made my country to be seen as an unsafe place for foreigners and even for locals.
Ecuadorian reality:
It's so common to see the Ecuadorian army and the police patrolling together against the crime in Quito's streets, but it's not enough.... Thieves, robbers, killers and rapists can be put in jail easily (if caught), but they are set free the following day.
I'd say Ecuadorian Legal System is one of the most corrupt of South America... this is the only country where a thief after been caught has the right to leave jail the following day if the value of the item robbed by him/her doesn't exceed the USD. 600,00. (crazy!!)
I've been object of a robbery in Rucu Pichincha as well (10 years ago). I never got any help from the police. Instead I had to take myself to the hospital to take care of my enjuries. The only thing I'd recommend is "avoid desolated places, and walk in large groups".. I know it's hard to prevent being robbed against a gun or a sharp object, but this could help.
I didn't know about this last bad experience, not even for the news, but for SP forum. I guess police's priority was to take more care of Quito's parties and festivities than for the rest of us up there.
Ecuador, a beautiful country:
Besides everything, Ecuador is such a beautiful country full of amazing places as the Amazon, the Andes, the Pacific Coast and the Galapagos Islands... its people are helpful and friendly, and although sometimes in strange ways... they are always ready to help the tourist in any situation.
I've been robbed in Peru twice, it wouldn't be fair to judge that amazing country just for a couple of assholes who only try to destroy a country's good image. Hope to visit it soon as I hope not many people would change their minds of visiting mine.
Anywhere in the world there are good and bad people, safe and unsafe places.. it's our job to take care of ourselves and to be cautious.
Once again I'm so sorry for what happened last Dec 7 2007, It's good to know the rapist finally got caught by the police for the peace of mind of all of us.