There’s some type of proprietary mesh - perhaps it’s metal - component in the straps so someone would have to work really really hard to slice the strap, if at all. The PacSafe website does a great job of showcasing all the anti-theft features in each bag or pack. Anti-theft is their entire brand niche so if a feature is not impossible to defeat, then surely it would take a little more time and effort and hence deter thieves to move on to another target.