Disgruntled Google AdWords advertisers noticed a few days ago that Google automatically turned on "automatic matching" on their campaigns. The first reports seem to have come in at WebmasterWorld on Thursday.
Here is one post showing their distaste for such a finding:
I just noticed Automatic matching total/Enabled/no clicks or impressions at the bottom of my keyword stats and I am not happy.
It turned out to be a bug that Google fixed a couple of days later. Google issued this statement to concerned advertisers:
Due to a bug in our AdWords interface which surfaced early this morning Pacific Time, you may have seen a message indicating that Automatic Matching was enabled in your account even though you had not turned it on. This message was added to some accounts by mistake and the error will be corrected today. No charges to any advertiser will result. We apologize for any inconvenience this has caused.
This was handled very well by Google, even though they seem to be spewing bugs out all over the place these days.
Forum discussion at WebmasterWorld.