Total membership

In my search for a new KatKwiz question I found this:

Under TCS statistics at the bottom of the page it says there are 26,660 members (now) but when I click on Member's List, it gives me a total of 24,142 (now). Where are these 2518 "invisible" people?

I would have loved to have given this as a KatKwiz question, but I could not do that when I do not know the answer and it is driving me crazy at these two different figures that are being reported.

The discrepancy is due to spammers, trolls and just people who never bothered to activate their accounts. The member list shows members with active accounts only, while the number at the bottom of the main page shows every registration, activated or not.