I grew up in Earthquake Country, Southern California. If you saw the recent movie with Dwayne Johnson called "San Andreas" then you have a glimpse into some of my worst fears. Obviously the movie was very "Hollywood" so you have to take it with a grain of salt.
Here's what's real though. . . furniture can fall over. When I was 5 I was lying on the floor watching "Duck-Tales" when an earthquake hit. On the wall next to me was one of my parent's bookcases, and as the earth jostled underneath us, the bookcase started to wobble. As they taught us in school, I ran for the nearest table, dove underneath, and assumed my best "duck and cover" position. . . right as the bookcase crashed down right where I had been sitting.
More recently at a family gathering I had to run to the aid of a teetering bookcase that was set in motion by kids jumping up and down. I've heard a horror story about a free standing 75" flat screen tv's falling on it's face; which isn't only dangerous but a major financial hit as well. Moral of the story - ANCHOR YOUR FURNITURE.
To help keep you safe, we ship every one of our bookcases with wall anchoring kits. You can see instructions for how to install these anchors here. We settled on these anchors after researching many different types and styles. These are the perfect balance of ease of installation and strength. If you're more comfortable with a screw-gun and a hammer then there are a ton of options when it comes to anchoring. We don't care what you use, just use something.
Anchor your furniture, keep your family safe, keep your furniture safe, and thanks for reading.