Are We Truly Safe?

A lot of us rely on our common sense to help decide between different situations, but are they really as reliable as they seem?
For example, the phrase mentioned in the text "There's safety in numbers". Programs like 624-Walk are providing students with an escort at night so they can feel "safe". You can see the contradictions with this when you hear news articles such as this.
The article shows that even when in groups, in this case 2 people, you are not completely safe.

The mugging happened just south of Willard Residential College in Illinois. Another incident very similar to this, actually happened at an apartment complex on the U of M Twin Cities campus. Even though colleges stress the concept of "There's Safety in Numbers" we are not always safe.
However, there is a lot of truth to this saying. Criminals usually spot victims who are distracted, unaware of their surroundings, and are alone. The problem is is that muggings are multiply determined. For example, criminals are usually on the lookout for easy targets, so they can quickly mug their victims and get away without the high chance of being caught.
Some criminals however, may be in desperate need of money and don't care about the circumstances of the victim.
It is impossible to determine whether or not our "phrases" are going to be reliable at certain times, but we can learn that we cannot become cocky just because we are following our intuitions.
With your experience as students, has your common sense been helpful or hurtful most of the time?