I guess this means that if I feel happy and satisfied by butchering senior citizens I should do it to increase my vibrational frequency.

This is a load of crap. No new ager has exhaustively explained what the hell they are talking about when referring to "vibrational frequency." What is vibrating that you wish to change? Through what medium does it vibrate? What are the properties of this medium such that we can conclude that "positive" thoughts (subject to change person to person, by the way) increase "frequency" of whatever the hell you are talking about, and "negative" thoughts (subject to change) decrease? And with all this in mind, what exactly is the point to doing so? Why is a lower vibration undesired? Why can I not gain from a lower vibration what a higher vibration is alleged to bestow?

If you're going to talk about vibrational frequency, then talk about vibrational frequency, oscillation, attenuation, propagation. Don't change the subject onto thoughts, feelings, positivity and the assorted conglomeration of fluffy ideas the New Age movement superposes upon these physics concepts.