I think, for the most part, the internet in general has heightened fear by making it easier to hear about all the terrible things in the world. Those crimes are not a new thing. In some ways, it can actually make it safer by making the names and faces of at-large criminals much faster. The fear is DEFINITELY more prevalent for most people -- I live in a town with an extremely low crime rate, and almost zero violent crimes. I still see people on the community groups trying to drum up hysteria, and reading gunshots into everything from firecrackers, to blown transformers, to the ice breaking up on the canal. Many people on there bemoan the loss of their safe community and keep their kids within tightly controlled areas...yet the statistics show an even lower crime rate than 10-15 years ago here.
Certain areas really have gotten more dangerous, internet or no. My husband grew up in Detroit, in a neighborhood that was once filled with families that let their children play in the streets. Now that neighborhood is filled with vacant buildings housing all types of squatters and illegal activity, and the city can no longer afford to keep the police force in that part of the city.
So yeah -- just like it's always been, crime rates go up and down in various areas for various reasons. While the internet improves communication regardless, I can't see it as a direct causative factor in the crimes. It does allow a lot more "dumb criminals" to be caught after they post about their activities on Facebook, though ;). Has it made parenting tougher? Maybe, but I'd be inclined to say "no" there too -- it adds another element that children need to learn to use responsibly and safely, but so does the existence of drugs, alcohol, firearms and "questionable characters" in their "real world" sphere.