“WARNING! Children let unattended will be sold to the circus” is a jocular warning that has been printed on many signs. The sign reminds parents to look after their children.
 
“At a candy shop in Port Dalhousie, there’s a sign saying ‘Children left unattended will be sold to the circus’” was cited in print in July 2006. The popularly printed sign appears to date to 2006.
 
 
Google Books
England
By Guy McDonald
London: Cadogan Guides; Guilford, CT: Globe Pequot Press
2003  
Pg. 656:
Busy, popular Adnams pub with crowded walls, good fish and chips and a sign warning that ‘any tourists left on the premises will be sold to the circus’, so make sure to put this book well away in your bag before entering.
   
Customers Suck!
Chantal
07-08-2006, 02:58 PM
At a candy shop in Port Dalhousie, there’s a sign saying “Children left unattended will be sold to the circus” Oh, how I wish it were true!:devil:
     
LOLhome
Children will be sold to the circus
(Sign is shown—ed.)
This funny picture was added on 29 December 2006, 20:39:53.
 
Google Books
To the Manor Drawn
By Leslie Ann Bosher
Sydney: Murdoch Books
2007
Pg. 213:
And who could fail not to snicker at a notice in a bric-a-brac shop window warning that ‘Unruly children will be sold to the circus’.
 
Etiquette Hell
TF298
Re: Unattended Children Signs
« Reply #9 on: January 08, 2007, 05:13:19 AM »
One of my MSN icons reads:
Warning:  Children left unattended will be sold to the circus.
 
Google Groups: rec.outdoors.rv-travel
Robert Bonomi  
3/4/07
A local store has a sign on the entry door:
 
Unattended
children
will be sold
to the circus!
 
Facebook
WARNING :: Children Unattended WILL Be Sold To The Circus
(Joined Facebook on February 16, 2010—ed.)
 
ESPN
Texas Rangers taking a stand against the wave
By Danny Woodward
Updated: July 29, 2011, 3:10 PM ET
Texas Rangers fans have plenty to cheer about these days: Their team holds the American League pennant and currently leads the AL West.
 
Whoop and holler all you want, Rangers fans. But whatever you do, don’t do the wave. It’s prohibited in Rangers Ballpark.
 
At recent games, a warning has appeared on the stadium’s message board claiming the wave could cause injury and that children doing it will be sold to the circus.
 
Twitter
Giselle‏
@GrumpyMoll  
Funny sign outside antiques shop: “Children left unattended will be sold to the circus” (snigger)
12:03 PM - 25 Jul 13