jimbeetle - 8:22 pm on Nov 18, 2012 (gmt 0)
Before getting into any conspiracy theories I think you have to go deeper into your analytics to find out what's what. Just saying that you lost 30% of your traffic in the last week doesn't tell you or anybody anything at all.
Which keyword phrases lost traffic? Which pages lost traffic? Is time of day or day of week in play? etc.