KingofGnG: You missed the point here.... Gmail isn't a simply mail server, it's a "web mail" that became an "off-line" mail client (well, sort of...) not so long ago, and it one of those things from which this meme called "cloud computing" should become to conquer the users' PC. Bullshits, aaaall bullshits.
hansschmucker: How is that missing the point? GMail is a service that people use because it's more comfortable than setting it up yourself. It's a prime example where software as a service makes sense... maintaining it yourself is a bitch, so you hand it off to a provider that can do a better job. Simple as that. Yes, it fails from time to time, but if you did it yourself downtime would be even worse AND you'd have to spend time and resources on it. I'm using GMail, eventhough I have a ready to run server myself which is running 24/7. I just don't care enough about it to maintain it myself. Whenever the cost and effort for setting it up myself is higher than what a service provider asks for, I use a service provider.
And what have virus infected ads to do with it?
I think the point that KingofGnG is trying to make is professionals can't trust an online service to maintain their data or run business critical applications like e-mail when it can simply go offline like that. Consider this: if cloud computing becomes the standard and everyone switches to internet mail like G-Mail and it goes offline, then multiple businesses cannot function. At least with an in-house e-mail server, when it goes down, only that one business is affected, not dozens of businesses across multiple countries. For personal uses, internet mail services like G-Mail are fine, but for professional uses, it's just too risky.
I believe the point of the ad virus story is just another example of what can and most likely will go wrong with cloud computing. Right now, getting a virus infection usually requires some type of manual action on the part of a clueless user (such as opening an infected e-mail attachment), while the more educated user is smart enough to not take that action (or use antivirus). With these malicious scripts, even that educated user is vulnerable, since all they have to do is visit an otherwise trusted page and the malware runs itself. The potential for a malware pandemic is huge.