A couple days ago I heard something about "goons killing a bunch of freighters".
Today the tl;dr is up on mittens.com and reads: A gank squad has killed 200 freighters since August.
So how much danger am I in?
First, frequency. 200 freighters in about 2-ish months is about 100 freighters per month. For the purpose of this post, we assume that every freighter passing through jita 4-4 has an equal chance of being ganked.
The equation for my risk, therefore, is: Number of freighters which pass through jita per month, divided by 100, multiplied by the number of times I pass through jita per month.
To find the first value, I watched the jita undock for 3 minutes. 14 freighters undocked. I divided this number by 2 because my observation was done at a peak time. 7*20*24*30 = 100,000 freighters per month, divided by 100 equals a 1/1,000 chance of being ganked per run. I do about 40 runs per month, so my risk is 1/25.
My maximum cargo plus hull price is about 2.7 billion, so during an average month I will lose 108 million isk to ganks.
Note: This assumes that the gankers target jita, which apparently they don't.