, ▁Group ▁ 4 , ▁a ▁security ▁firm ▁formed ▁in ▁the ▁ 1 9 6 0 s , ▁merged ▁with ▁Fal ck ▁to ▁form ▁Group ▁ 4 ▁Fal ck ▁and ▁by ▁ 2 0 0 0 ▁the ▁company ▁was ▁described ▁as ▁" the ▁world ' s ▁largest ▁private ▁security ▁systems ▁company ". ▁In ▁ 2 0 0 2 ▁Group ▁ 4 ▁Fal ck ▁went ▁on ▁to ▁buy ▁The ▁W ack en h ut ▁Corporation ▁in ▁the ▁United ▁States . ▁▁ 2 0 0 4 ▁to ▁ 2 0 1 0 ▁G 4 S ▁was ▁formed ▁in ▁July ▁ 2 0 0 4 , ▁when ▁Group ▁ 4 ▁Fal ck ' s ▁security ▁business ▁merged ▁with ▁Sec ur ic or ▁to ▁create ▁Group ▁ 4 ▁Sec ur ic or ▁and ▁began ▁trad ing ▁on ▁both ▁the ▁London ▁and ▁C open hagen ▁Stock ▁Ex changes . ▁In ▁ 2 0 0 5 , ▁Lars ▁N ør by ▁Joh ansen ▁was ▁succeeded ▁as ▁chief ▁executive ▁by ▁Nick ▁Buck les ▁and , ▁in ▁ 2 0 0 6 , ▁the ▁new ▁G 4 S ▁brand ▁identity ▁was ▁rolled ▁out ▁across ▁its ▁business ▁world wide . ▁In ▁the ▁same ▁year , ▁Alf ▁Duch - P ed ers en ▁succeeded ▁J orgen ▁Philip - S or ensen ▁to ▁become ▁the ▁non - exec utive ▁chairman ▁of ▁the ▁business . ▁ ▁In ▁ 2 0 0 6 , ▁ 2 0 0 7 ▁and ▁ 2 0 0 8 , ▁G 4 S ▁was ▁the ▁subject ▁of ▁a ▁global ▁campaign