fail to steal a porch packet, but on camera, is it a crime?
these failed stealings on camera, what punishment to they receive?
If in the US, they could be charged with mail theft.
If I try to stab you to death, but I fail, is it a crime?
Generally, as long as there is proof you attempted a crime, it's a crime. However, punishment is often lower than when you succeeded, if only because there are is damage done.
Glitter Bomb (https://www.youtube.com/watch?v=3c584TGG7jQ)
This YouTuber, Mark Rober, is doing something about it!