This happened to me as well, for the Pride parade this year. I had looked up the parade route and obviously didn't park there, but I got home the night before the parade (pretty late, around 11pm) and parked on my street as normal. There were no signs posted and everyone was parked on both sides, also as normal. In the morning, I woke up to a ton of beeping from the tow trucks moving my whole street of cars. Luckily they hadn't lost my vehicle, but I did get a ticket for parking in an "emergency no parking zone" and another one for the relocation fee. $150 all in. I contested and they rejected, so good luck. :(