Official Gmail Blog: Detecting suspicious account activity.
I found this article interesting. Google has implemented a kind of security feature in Gmail. What it looks like, is now Google keeps track of the IPs that you log into your Gmail account from (which they have for awhile now, check this out from back in 2008) and let's you know of any very strange deviations in pattern.
The example they provide is this:
Google knows, in this example, that this person normally signs in from California in the USA, then suddenly in the middle of all the normal accesses, there is a login in Poland. Which is strange for the user, and you get this popup when you log into your gmail:
I think this is head and shoulders above what any of the other competitors are doing with their free online email solutions, and hopefully this will make strides to curbing some spam and illegal access of accounts.
No doubt that this had something to do with the illegal access of accounts from China during the whole "Google/Intel/insertothercompanieshere debacle". Glad to see Google doing things like this.