I managed to get some historical data points from the archive.org by asking for this page. Unfortunately, the archive.org is having technical difficulties and I cannot get more data points right now. But you get the idea.

The first data point below, in February 2006, was when a couple of editors began formulating a BLP policy. Jimbo gave it his blessing a few months later, and a weak BLP policy was put in place in July 2006.

Total number of entries in "Category:Living people"

2006-02-10: — 68,684

2006-07-19: — 109,854

2006-10-08: — 131,046

2008-03-12: — 263,487

2009-12-22: — 422,899

How should we interpret this data?

1. The efficiency in tagging such articles has improved. (Yikes! — this implies that today there may be a lot more than 422,899 BLPs.)

2. All the publicity regarding Wikipedia's BLP problem meant that bored basement-dwellers realized that they can add obscure people as easily as names of obscure high schools, and increase their edit count. This is how they become a kick-ass administrator on the greatest role-playing game on earth.

3. The Arbcom, which is the highest policy body save for Jimbo, Godwin, and the Foundation, should be disbanded because it is unable to address the most serious problem on Wikipedia.

4. Jimbo sent a train down the track at full throttle without an engineer, and he pretends it's an encyclopedia.

5. The Foundation is begging for a class-action lawsuit because they cannot stop Jimbo's train, and need a judge to tell them what to do. Meanwhile, the donations coming in are quite comfy, San Francisco is a lot of fun, and there's no hurry.

Thank you tarantino, who came up with this link. It provides a random sample of a BLP article. See for yourself what sort of quality we get on Wikipedia. Remember, Facebook may have 350 million entries, but the subject started his or her own entry on Facebook. On Wikipedia, some basement-dweller started it on another person without asking for permission. Moreover, Wikipedia ranks infinitely higher than Facebook on Google.