There are posters all over 'the strip' in Cardiff which warn you not to leave your bag open and mobile phone on display while on a night out etc, with a picture of a hand sneaking up behind someone and taking their phone. Above it, in big text, it says something like "When a thief call's don't let him answer the phone!". Not only does that make zero semantic sense, but these posters are ALL OVER THE CITY CENTRE and it blows my mind how many hands this design must have passed through without anybody noticing the glaring error. Call's isn't even a word, god damn it.

There also used to be big police notices on lamp posts saying "CCTV IS IN AFFECT IN THIS AREA" before some buff bod must have pointed it out and SW Police took them all down.