In a study by Venafi from 2007 (referenced here), 18% of the Fortune 1000 websites had expired SSL certificates. If that ratio still holds true, and holds true for the rest of the Web as well, it means that in addition to the 1 million websites with valid SSL certificates there are 219,000 websites with expired SSL certificates.
For those who don’t know what does SSL mean, SSL means Secured Socket Layer which was created by Netscape to ensure secured transaction between web servers and browsers. The protocol uses a third party, a Certificate Authority (CA), to identify one end or both end of the transaction.
Because of this, the Spam, viruses, spyware, phishing attacks are increasing rapidly now a days. The results are such that Spyware caused 850,000 households to replace a computer in the last 6 months. The detailed graph is like this,
Such incidents are an awakening call for those website owners to re-activate their SSL certificates so that people who are browsing their sites can go ahead without any fear.