This sign is funny because a warning of this nature is largely superfluous. JOKE EXPLAINED.
This sign is funny in that it states the obvious problems associated with a sign advertising a temporary issue. JOKE EXPLAINED.
The 'sorry' addition is what is funny about this sign. Signs are designed to state information clearly and professionally and the 'sorry' gives the sign a human element that is uncharacteristic. JOKE EXPLAINED.
The quote marks on this sign are where the comedy lays here. It shows that the sign creator sees the security guards as being largely ineffective. JOKE EXPLAINED.
This sign is less funny and more a statement about how much the sign owner values sarcasm. JOKE EXPLAINED?
This sign is important, but it is humorous that this weird problem is so pervasive that a sign needs to be created to address it. JOKE EXPLAINED.
The original sign creator being 'shut down' by the second sign creator in such a forceful manner is what causes this exchange to be funny. JOKE EXPLAINED.
This picture is funny because the person who made the sign was clearly frustrated enough about this problem to make a sign about it. JOKE EXPLAINED.
This sign is funny contextually because usually when someone is memorialized it's because they love that place or thing. Not so with this plaque. JOKE EXPLAINED.
This is a pun designed to show the sign tweaker's distaste for Fullerton. JOKE EXPLAINED.