heightened alert. let's take a listen. >> i've got confidence in the spro superior system and the staff and we have watched tv quite a lot today and quite confident they are doing everything they need to do to make sure everybody is safe. >> obviously, a bit nervous but at the end of the day you trust the people doing their jobs. we don't mind coming a bit early to get the right scans done and that sort of stuff doesn't happen. >> some other passengers we spoke to are used to seeing this play out overseas and not on australian home soil. this is the 15th foiled terror plot in the country. there has been a sharp increase in the number of terror cells and home-grown terrorists since 2014. isis-inspired. you have to say there is significant concern that because this involves planes and