Hi Riverkid!
Well, I should have used "many people" instead of "others".

My basis for saying that is:
1) Assuming technical data refer to specifications or a set of data, and thus to individual items of data, it should be treated as a plural noun. (I may be wrong here.)
2) The results of my googling "are" vs. "is" are as follows:
technical data are: 21,400 hits
technical data is: 40,600 hits
technical data include: 2,260 hits
technical data includes: 3,770 hits
Although I realize that data from Google cannot be trusted 100%, I get the impression from the results that the term "data" is used somewhat loosely in terms of "singular vs. plural".
I think it is safe to say that we do not have the concept of countable and non-countable nouns in the Japanese language. In fact, I think all nouns are countable. But, we do not change the form of nouns like you do in English when using nouns in the plural. And borrowed words are no exceptions. And this, of course, makes it difficult for many Japanese learners of the English language to grasp the concept of "countables vs. non-countables", particularly to know when a non-countable turns into a countable and vice versa (a BIG sigh).:roll: