Sentence:  Thousands of violent videos are still available on the internet, according to Alexander, who claims they lead to an escalation in <WSD>offline</WSD> tensions between rival gangs. "I believe some young people are losing their lives as result of this material on the internet," she said. 
Meaning of the word marked with <WSD> tags:  Happening in the physical world (the real world) as opposed to on the internet.