Wally (anonymous)

Wally is a British English expression referring to a "silly or inept person", which later developed into an umbrella term for "vulnerable individuals".

According to Oxford Dictionaries Online, it possibly originated at a pop festival in the 1960s when, on hearing the name being announced many times over a loudspeaker, the crowd took it up as a chant.

The cry was picked up by others and led to random shout of "Wally" being heard at rock concerts all over Britain. It was still being called out at the 1979 Led Zeppelin Knebworth Concerts.

In 1974 a group of new age travelers were encamped near Stonehenge, to help hinder the process of eviction by the landowners they all gave their name as Wally of Wessex, "Wally being a conveniently anonymous umbrella for vulnerable individuals".

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Wikipedia