25% of all computers are part of a botnet

Vint Cerf, one of the most respected 'fathers of the Internet' (up there with Tim Berners-Lee, or Sir Tim as he is now known) has stated his belief that as many as 1 in 4 computers is part of a botnet.

Cerf, was speaking at the World Economic Forum this week:

"Cerf told his listeners that approximately 600 million computers are connected to the Internet, and that 150 million of them might be participants in a botnet—nearly all of them unwilling victims."

If true, this is a staggering statistic and shows the challenge that ISPs have to identify, contact and cleanup customers who are affected.

If you look at the latest numbers from ISP Review for the top 10 broadband ISPs in the UK, the challenge on a per ISP basis becomes clear:

Number of broadband subscribers per ISP

No. Name Subscribers
1. BT Retail 3,000,000
2. ntl:Telewest 2,980,400
3. AOL UK 1,523,000
4. Tiscali 1,400,000
5. Orange 986,000
6. TalkTalk (CW) 632,000
7. Pipex 570,000
8. Virgin.net 242,800
9. PlusNet 198,000
10. Kingston 140,851

Adjust this on a per-ISP basis based on Vint's comments, and you see the impact:

Numbers of customers each ISP might have in a botnet

No. Name Customers
1. BT Retail 750,000
2. ntl:Telewest 745,100
3. AOL UK 380,750
4. Tiscali 350,000
5. Orange 246,500
6. TalkTalk (CW) 158,000
7. Pipex 142,500
8. Virgin.net 60,700
9. PlusNet 49,500
10. Kingston 35,212