Advertising agency Goss went a little guerilla/ambient overboard when shilling their bike client. Their idea was to paint "bike lane" symbols on places where it is impossible to ride a bike. They even painted some on the highway.
After a few days someone at the agency came to their senses and they decided to remove that particular one.
The Swedish Road Administration describe the idea as highly dangerous and point out that one needs to seek permission before placing signs on or near roads.