In a turn of face by Google regarding handling of optimisation issues, Matt Cutts has confirmed that a number of webmasters have received letters from Google notifying them of penalisation problems with their websites, the first of which focuses on the use of JavaScript redirects.

Matt said: "Google is trying out a pilot program to alert site owners when we’re removing their site for violating our guidelines. JavaScript redirects are the first trial, but we’ve also sent a few emails about hidden text, I believe. This is not targeted to sites like buy-my-cheap-viagra-here.com, but more for sites that have good content, but may not be as savvy about what their SEO was doing or what that “Make thousands of doorway pages for $39.95″ software was doing. Personally, I think opening up a line of communication to let webmasters know when we’re taking action is a really good thing–a site owner doesn’t have to guess about what happened. But again, we’re starting with a trial program."

This positive step by Google seems to really re-emphasise the need for an enterprise approach to SEO work that falls within the guidelines provided by the engines. If you're a big brand you really don't have any other choice, because your long term online business is at stake.
In a blog post of ours from earlier in the year I discussed why bridging pages which often use Javascript redirects are fundamentally flawed.

Using these types of bridging pages and redirects can trigger penalties from Google, as is now proven.  Even if you look beyond the penalisation potential, they'll never attain any link popularity from users bookmarking or linking to the pages, and as links are the fundamental basis of current ranking algorithms, without them how are you going to improve positioning?

If you receive a letter or penalty you've got a business continuity problem on your hands. You're probably not going to get any business from organic search for 30 days or more, you will also have to remove the redirects so everyone will see what you're doing, so therefore you'll need to remove the bridging pages as well and you'll be no further forward regarding organic traffic. In fact you'll not only have an optimisation project on your hands you'll have a clean up project as well because someone is going to have to work out how to handle the strays from the from the removed pages.

Anyhow sending out these letters is a good move by Google, and shows a sensible approach to educating webmasters and SEO's. But the warnings might be more useful if they were received before the websites get penalised :-)