Not all pods are free from errors or anomalies.
Sometimes small glitches can cause major consequences...
Sleeping pod caged humans connected to a world they take as ''Normality'' and ''the truth'' all as we know now as a fabricated lie to keep us under the spell.
All it takes is a small surge in power or maybe a small tweak to the system and an anomaly is born.
The machines scan for these changes in the pods more and more after the war and the surge in stronger Human RSI within the matrix and the awakening of the humans...
High Brain activity humans are classed as high risk. And are often removed from the system or monitored to prevent damage. But sometimes one slips through.
We all know of the famous 'The One', We know there won't be another like him but the organisations are searching for a 'High brain activity' RSI that possibly has slipped through and maybe will have the ability to morph the code to see fit... This RSI won't even know it which lengthens any search. The System is unaware as of yet and the organisation that gets it might have the upper hand.
Organisations are scrambling to find this 'RSI' and attain the knowledge of maybe finding if it has these abilities or is it just a clever bookworm who has no special qualities and is just eager for knowledge... Fact is chances like this are rare.