This is art... and intended to be. As you can see, this sticker is posted on a stoplight. It might appear to be a social service agency but at closer inspection it is not. I tried calling and in fact you do get an answering machine that prompts you to leave your apology at the tone. Apologies are all recorded and anonymously replayed or transcribed.
This project was started in 1980 by artist Allan Bridge. Their have been books, magazines, a play and even a couple of films based on this. The project ended in 1996 when Bridge died in an accident. However, obviously this is operating again.
Here are some links with more info and gut wrenching audio samples: Apology Line