They make it too easy. Cheap windows. Video that demonstrates the varying levels of security provided by different grades of security glass. Included are EN356 Resistance to manual attack glass, LPS1270 Intruder Resistant Glass and EN1063 Bullet Resistant Glass. Look how tough the stuff at end of video is.
How Much Does Security Film Cost? You can expect to pay between $14 to $16 per square foot of glass. How Much Does Riot Glass Cost Riot Glass is $25-$34 SQ FT. How Much is UL Level 1 Ballistic Laminate? Laminates start at $200 a SQ FT. I don't think it has to be bulletproof I think just the riot glass would do it. Just seems so incredibly stupid to have millions of dollars worth of stuff in a store behind windows what become open doors after one brick toss.
Someone tell these protesters/vandals you only need to break a window once. All that extra smashing is wasted energy.