Ending a relationship by writing "it's over" on a sticky note is an example of the poor usage of which component of communication?

This is a poor use of the Communication Channel. These are the physical instruments that help in communication such as writing, email or cell phone. This channel facilitates communication, widens it and allows the message to be transmitted more quickly. In this case, the use is poor because the note is very short and this type of messages is better to give them face to face.

Freedom of religion, freedom of speech, being protected by our military and first responders on a daily basis and many many more.