Running the following query:

http://api.stackoverflow.com/1.1/comments

Yields:

{
  "total": 0,
  "page": 1,
  "pagesize": 30,
  "comments": [
  ...

Notice that the total entry indicates there are 0 comments on all of StackOverflow! I know that this can't be right, because the comments array has 30 items in it.