What were they thinking?

Usually there's a process for posters.

It starts with the "creatives" having a brain storm, then a final slogan is chosen, then a graphic designer makes it on a computer, then a final sign-off and then the printers and THEN the lads who put the posters up.

So, erm. How did nobody see this?

This one must have a been a brain fart not a storm.

This firmly has to fall into the You Had One Job Category.