I think the point would to be make them like cigarette warning labels. At the moment the text can be hidden on a bottle or can in tiny text. It needs to be a big ugly white box with a black border and large text that gets people's attention.
From my understanding, you are pretty safe as long as you don't provoke them (walking through the middle of them might be considered provoking) or near their calves. This article from the UK states "Where recorded, 91% of HSE reported fatalities on the public were caused by cows with calves". Basically, mothers with a child are going to be very protective.
Cows are a domesticated creature, so they are generally docile, but I would exercise caution because if need be they will use their mass and strength against you. I've heard of stories of farmers running from cows and narrowly escaping under a fence. Most of these did involve a farmer trying to separate a calve from it's mother. I've also heard stories of cows jumping fences.
This would only affect the 12V rail though no? It's not like they are beefing up the 5V rail that supplies your USB ports in excessive amounts. Picking a random PSU from pcpartpicker, the CORSAIR RM650e vs RM1200e (650W vs 1200W) both have a +5V@20A rail. There would be no need to have a larger 5V rail to support gaming cards.
Also correct me if I am wrong, most PSU's are more efficient at 20-50% utilization, not 100%. I'm basing this off the higher ratings for 80 Plus.
Your computer doesn't "waste" electricity, power usage is on-demand. A PSU generally has 3 "rails"; a 12V (this powers most of the devices), a 5V (for peripherals/USB) and 3.3V (iirc memory modules use this). Modern PSUs are called Switched-mode power supplies that use a Switching voltage regulator which is more efficient than traditional linear regulators.
The efficiency of the PSU/transformer would be what determines if one or the other is more wasteful. Most PSUs (I would argue any PSU of quality) will have a 80 Plus rating that defines how efficiently it can convert power. I am not familiar enough with modern wall chargers to know what their testing at.. I could see the low-end wall chargers using more wasteful designs, but a high quality rapid wall charger is probably close to if not on par with a PC PSU. Hopefully someone with more knowledge of these can weigh in on this.
