Quoted from CLEllison:

Sounds like you got grumpy old man syndrome going on. I should know, I find myself getting irritated when people park in front of my house only to walk up the street to someone elses house instead of parking in that persons drive way. Shit drives me nuts! Ask yourself, "Are they breaking the law?" The answer is likely found in local law ... how many days can a vehicle sit without moving. In my case no, they aren't breaking in laws. The street/road is considered public property.