Ok, I can give a truer answer then.
The acidity of an acid depends on the stability of it's conjugate base - the more stable the conjugate base, the stronger the acid. One of the biggest factors contributing to stability is electron delocalization. By electron delocalization, I mean the electrons have more space to move around.http://www.chemguide.co.uk/inorganic/period3/clo4a.gif
That's the structure of the perchlorate anion. Due to resonance effects, the negative charge is actually shared equally between all 4 oxygens, to give this structurehttp://upload.wikimedia.org/wikipedia/commons/7/7c/Perchlorate-2D-dimensions.png
The negative charge (electrons) are spread out over a large area on several electronegative atoms (which are happy to accept the partial negative charge, due to their electron affinity). The combination of these things leads to a stable conjugate base.
Applying this info to my previous post - perchloric acid exhibits resonance too - there just exists a formal positive charge on the oxygen attached to the hydrogen and a formal negative charge on the other oxygens. The other oxygens are resonance electron withdrawers, which means there is less electron density near the hydrogen, making it more prone to dissociate.