It is possible that someone could use a leatherman to cut through the mesh, but it would take a while to get through enough that they could remove your pack, I think they'd be more likely to pick up another unsecured pack and walk off with that.

But pacsafe isnt just about the pacsafe mesh, they now make a whole range of products, which have the mesh actually built into the fabric, so they look like regular bags but have security built in.

I use a metrosafe 300 laptop bag which is great as when I'm travelling if I want to sleep in an airport (for example) I just lock the metrosafe to my seat and can get some shuteye without worrying that someone might walk past and casually walk off with my laptop and everything else. I know people that have had that happen and I recommend the pacsafe metrosafe to everyone I meet.

Sean