A well aired conspiracy theory is the one regarding chem-trails, the emissions from planes that are some sort of experiment by the Government to in some way control us.
Of course the Tory Government may be called the nasty party but even they wouldn't spray the population with chemicals from aeroplanes, or so you would think if you didn't know that spraying the British population with chemicals from planes was exactly what they were doing between 1940 and 1979.
A government report tells how they released potentially dangerous chemicals and micro-organisms over vast swaths of the population as a test without the public being told.
While details of some secret trials have emerged in recent years, the 60-page report reveals new information about more than 100 covert experiments testing the reaction if the Russians ever released clouds of deadly germs over the country.
One chapter of the report, 'The Fluorescent Particle Trials', reveals how between 1955 and 1963 planes flew from north-east England to the tip of Cornwall along the south and west coasts, dropping huge amounts of zinc cadmium sulphide on the population.
In another trial using zinc cadmium sulphide, a generator was towed along a road near Frome in Somerset where it spewed the chemical for an hour.
While the Government has insisted the chemical is safe, cadmium is recognised as a cause of lung cancer and during the Second World War was considered by the Allies as a chemical weapon.
In another chapter, 'Large Area Coverage Trials', the MoD describes how between 1961 and 1968 more than a million people along the south coast of England, from Torquay to the New Forest, were exposed to bacteria including e.coli and bacillus globigii , which mimics anthrax. These releases came from a military ship, the Icewhale, anchored off the Dorset coast, which sprayed the micro-organisms in a five to 10-mile radius.
The report also reveals details of the DICE trials in south Dorset between 1971 and 1975. These involved US and UK military scientists spraying into the air massive quantities of serratia marcescens bacteria, with an anthrax simulant and phenol.
Despite the MoD stating that these tests were safe with no risk to public health, some families in areas which bore the brunt of the secret tests are convinced the experiments have led to their children suffering birth defects, physical handicaps and learning difficulties.
When asked whether such tests are still being carried out, a MOD spokesman said: 'It is not our policy to discuss ongoing research' which you can make of as you will.
Chem-trails then, if it is later discovered they are doing something a bit evil to us without our knowledge, it wouldn't be the first time much of Britain was exposed to god-knows-what sprayed from on high in secret trials.