Honestly, I am only irked when people insist that data must be used as a singular or that it must be used as a plural. You'll find it listed both ways in good dictionaries:
> Both constructions are standard. The plural construction is more common in print, evidently because the house style of several publishers mandates it.
The commentary is a subset of what's in the wonderful M-W "Concise Dictionary of English Usage." The entry for "data, datum" starts "The word data is a queer fish."
- data isn't an ordinary plural. "Ordinary plurals ... can be modified by cardinal numbers; ... no one, it seems, can tell you how many data."
- "To summarize, data has never been the plural of a count noun in English. It is used in two constructions - plural, with plural apparatus, and singular, as a mass noun, with singular apparatus. Both constructions are fully standard at any level of formality. The plural construction is more common. If you are an editor for a publisher whose house style insists on the plural construction only, take care to be consistent ..."
- "There have been more occurrences of datum in popular sources since [about the middle 1960s]. Perhaps the insistence of many editors that data is a plural has accelerated the tendency for datum to be used as a singular of data"
Languages change slowly over time. I find myself using plural data when I'm talking science and singular data when I'm talking about hard drives. Hadn't noticed until your post!
> Both constructions are standard. The plural construction is more common in print, evidently because the house style of several publishers mandates it.
http://www.merriam-webster.com/dictionary/data