A possible concise summary is:
The transcript is an interview with a former undercover police officer who infiltrated a group of football hooligans from Millwall. He talks about his experiences, challenges, dangers and outcomes of his operation. He also reflects on how the job changed his views on football and the police. He reveals that he left the police force at 23 after his operation was abruptly shut down due to other officers fabricating evidence. He describes some of the most memorable and disturbing incidents he witnessed or participated in, such as a violent attack on a Crystal Palace fan, a brawl with Arsenal supporters, and a confrontation with his targets. He says that the best thing about undercover work was convincing people that he was someone else, but also the most disturbing. He says that he started the operation as a kid and finished it as a man.
Some possible facts extracted from the text are:
- The speaker is a former undercover police officer who infiltrated a group of Millwall football hooligans for two and a half years.
- The speaker witnessed and participated in violent incidents, such as punching a man with a Crystal Palace badge, fighting with Arsenal supporters, and being confronted by other hooligans who suspected his identity.
- The speaker's operation was concluded abruptly without any arrests or trials, due to bad publicity and evidence fabrication in similar operations at West Ham and Chelsea.
- The speaker left the police force at the age of 23, after being disillusioned by the way football was policed and the lack of support he received from his superiors.
- The speaker enjoyed the challenge and satisfaction of convincing people that he was someone else, but also found it disturbing and emotionally draining.