AFAIK, there are three hazard levels.
1) LOX, liquefied oxygen is mainly a cold-burn hazard without some ignition source, though as it vaporizes it moves to condition 3.
2)Pressurized oxygen is a big hazard as it can cause hydrocarbons to spontaneously combust - mainly seen when someone uses petroleum grease on o-rings or leaves fingerprint oils on screw threads.The burning o-ring can be a high enough temperature to allow ignition of the metal. Metal fires are especially not fun.
3) Oxygen rich atmospheres are a particular hazard as those exposed to them don't have the feedback of the other two cases. For example - oxygen tents in hospitals. A small spark from electrostatic discharge that would not ordinarily be of concern can cause a rapid combustion of the materials the spark terminates in. This was the cause of the Apollo conflagration - no one gave much thought to a 15 psia oxygen atmosphere.
Note that the oxygen itself doesn't combust - it is the materials around it that do. A spark in mid-oxygen does nothing. A cigarette in an oxygen rich environment should burn vigorously, but not explosively and if it doesn't make contact with any other combustible, will rapidly extinguish. However, if the smoker is startled by the flare of the cigarette and drops it onto something else combustible, then look out for the runaway fire.
High pressure oxygen is used in medical and industrial settings all the time and I don't recall seeing it make the news. I think the hazard is so firmly presented that doing stupid things is largely avoided. (Then sees videos of oxy-acytelene gas mixtures put into party balloons and ignited. Sigh.)
The greatest hazard is a large number of oxygen generators loaded as unprotected cargo. Not only do they build sufficient heat to ignite other materials when triggered, they produce oxygen to ensure a robust fire, which cascades to operating all the other oxygen generators. Individually they contain no liquid or high-pressure oxygen and one could probably kick them around - unless the safety provisions weren't installed.