"The present state of civilisation is as odious as it is unjust. It is the reverse of what it ought to be, and it is necessary that a revolution should be made in it. The contrast of affluence and wretchedness continually meeting and offending the eye, is like dead and living bodies chained together."
- Tom Paine
(Photo - 24 hr strike in Greece)
More info on May Day stuff round the world here
The history of International Worker's Day (clue: no connection to tank parades or the Soviet Empire) here