Spam issues need to be considered from the start
A number of Google's issues from the spammer I talked about yesterday come down to issues of product design, where Google's design decisions opened them up to being used by a spammer. I considered these issues mistakes, because they fundamentally enable spammers, but I suspect that Google would say that they are not, and any spam problems they cause should get cleaned up by Google's overall anti-spam and systems that watch for warning signs and take action. Well, we've already seen how that one works out, but there's a larger problem here; this is simply the wrong approach.
In a strong way, anti-spam considerations in product design are like (computer) security. We know that you don't get genuinely secure products by just building away as normal and then bringing in a security team to spray some magic security stuff over the product when it's almost done; this spray-coated security approach has been tried repeatedly and it fails pretty much every time. The way you get genuinely secure products is considering security from the very start of the product, when it is still being designed, and then continuing to pay attention to security (among other things) all through building the product, at every step along the way. See, for example, Microsoft's Security Development Lifecycle, which is typical of the modern approach to building secure software.
(That you need to take a holistic approach to security is not really surprising; you also need to take a holistic approach to things like performance. If no one cares about performance until the very end, you can easily wind up digging yourself into a deep performance hole that is very painful and time-consuming to get out of, if it's even feasible to do so.)
Similarly, you don't get products that can stand up to spammers by
designing and building your products without thinking about spam,
and then coming along at the end to spray-coat some scanning and
monitoring magic on top and add an
abuse@... address (or web
form). If you want products that will not attract spammers like
ants to honey, you need to be worrying about how your products could
be abused right from the start of their design. By now the basics
of this are not particularly difficult, because we have lots of
painful experience with spammers (eg).