I have had that done on the sidewalk right in front of my house about monthly for a long time. After the first few times, I figured out was because I have a "Kindness" sign in my yard and occasionally signs for a Democratic candidate or liberal issue. It makes me angry, and I wish I could catch the perpetrator so I can remind him that it doesn't reflect on me; rather it represents who he is, a sack of sh--!
By the way, I'm on the eastern end of Scribe near MoPac. If anyone sees this person, please let us know!