I very much enjoyed Stephen Turner's recent blog post There is no Such Thing as Biomedical "Big Data" and I agree with his central point that a lot of the talk about 'big data' is not really what others would consider 'big'. Out of curiosity, I had a quick dive into Google Scholar to see just how popular this particular cliche is becoming. My search term was "big data" biology|genomics|bioinformatics.
Clearly, this term is on the rise and might become as much of an annoyance as another phrase I loathe: next generation sequencing. A phrase that has been used to describe everything from 25 bp reads from early Solexa technology (circa 2005) to PacBio subreads that can exceed 25,000 bp.