...is the maximum number that can be used on any one Lot.
I'm running TS2 Double Deluxe with all EPs and SPs except the Holiday Stuff SP.
Here's a pic:

The rows are 40 squares deep and there are 50 rows (Every tenth row is marked red). So, 40x50=2,000, plus two and one-half rows on top for an additional 100 makes 2,100 total wall sections.

I just wanted to see what it looks like.

I don't think anyone would go beyond this limit. So I guess everyone is safe.

Unless they're building something like 10 stories above on a 5x5 lot, then obviously they could cross the limit. (Don't build more than the game limit, its been known that the lot will crash.)