Certificates Still Not Valid
Back in 2001 I wrote about the differences of PKI and passwords after speaking at Secure Summit. Bruce Schneier talks about the situation in Internet Banking today, with most still using simple passwords.
This makes perfect sense because, still, certificates are vulnerable to theft and brute force attack.
There is an interesting attack on passwords, however, that most sites don't consider or protect against. If you only care about geting into an account, not a specific account then a brute force attack against name, rather than password is very viable. Simply take a password, or passwords, that somebody is bound to have then run through usernames to find the user who has it.
I came across a company recently who had actually made this form of attack very simple. They had decided that usernames based on your real name were obviously a risk so all usernames were instead a five letter random sequence, making it trivial to now run through and find a user (any random five letters) with pa55w0rd as their password.