The city of Chicago has become a top terrorist target ever since Barack Obama took office. Many terror groups refer to the city as "Obama town," given the city being Obama's home political turf.

Now, a chilling tweet from a purported IS terrorist puts a bullseye on the city.

CBS Chicago:

In the meantime, the U.S. government on Friday issued a security bulletin to all U.S. law enforcement in light of the overall threat posed by Islamic State, commonly known as ISIS or ISIL.

The ominous post on Twitter, purportedly from somebody connected with Islamic State, shows a photo of the Old Republic Building, 307 N. Michigan Ave., in Chicago and the White House.

The text reads:

#AmessagefromISIStoUS
We are in your state
We are in your cities
We are in your streets

You are our goals anywhere.

#AmessagefromISIStoUS
We are in your state
We are in your cities
We are in your streets

You are our goals anywhere http://t.co/1EYMgCWJse—
قهر الطواغيت (@Sunna_rev) August 09, 2014

The handwritten note is dated June 20.

The security bulletin issued Friday cautioned that there is no known threat to any U.S. cities

The Twitter message seems to imply that Islamic State operatives are in Chicago and other U.S. cities.

Islamic State is responsible for executing kidnapped journalist James Foley. Defense Secretary Chuck Hagel said ISIS an “imminent threat to every interest we have.”

Making things more complicated is the fact that these radicalized men are U.S. citizens or foreign nationals here legally, making it easy for them to travel and avoid suspicion.

Islamic State released a horrific video this week showing the beheading Foley, who was a graduate of Northwestern University.

I suspect no one really knows if Chicago, or any particular city is a target of IS terror plans. But tweets like the one above are not threats, as much as they are meant to scare people. Politicians are already playing up the danger of IS - overstating it in my opinion - using the threat as justification to advance their pet weapons system or military project. The threat is real, but the way to deal with it is to confront IS in the Middle East and remain vigilant at home.