As a technical SEO I get to audit a lot of websites, some good, some bad. By far one of the most common mistakes made by developers is not providing an XML sitemap for Google (and other search engines) to utilise.
In a move reminicent of the BD recruitment email blunder just over two years ago, location-based social network aggregator Footfeed have inadvertently sent an email to around 100 of their beta testers (including myself) *please see update below. The email (below) was asking the Footfeed beta testers to answer a survey regarding their service. My first thought would be to learn how to use the BCC field.