Last night, the first secret on PostSecret was a confession of murder, printed on card made of a GoogleMap.

PS readers took to Twitter under the hashtag #postsecret, myself included, to figure out if anyone else had seen the post. @Amanda_theRad began a thread on Reddit to help identify where the map pictured; it was identified as Jackson Park Driving Range in Chicago, IL. (The main thread was scrubbed for containing personal information but there is now a dedicated subreddit to discuss the case http://www.reddit.com/r/PostSecretCrÔÇŽ. r/WTF is being sensitive to potential vigilante activism post-Boston.)

It was also determined on the main thread that this is an older print out of a Google Map based on the button interface, possibly from around 2008. (I think this comment may have been deleted now; I can't find it to source.)
Another twitter user @lisawhite has already contacted the police asking that they visit the area but it's unclear what action has been undertaken.

I realize this all has the potential to be an elaborate hoax but at some level it seems unlikely; PostSecret is built on the anonymity of the people who submit secrets. Let's hope.