A lot of the bread and butter tree-felling is now done by harvesters or tree-shears.
https://www.youtube.com/watch?v=fwOrKizyuxA
They are cool bits of kit but I've only seen them clear cutting plantations, rather than removing an individual tree from a congested forest. Obviously you have to be able to get a decent-sized excavator into place. Wirecutting kit is man-portable.
The safest pace to be when a tree is being felled is right next to the trunk, assuming you know what you are doing. Dead branches are a problem, hence my concern that Ash dieback casualties are tackled sooner, rather than later. Dead branches tend to get rattled out of the canopy in high winds. It's poor directional felling that causes a lot of hung-up trees.
The casualty stats usually highlight those with access to chainsaws, but with no training.
Booby-trapping trees to prevent felling is an interesting area. I've done a lot of felling to improve the structural diversity of woodland, under the direction of conservation bodies. That can lead to MTB and motorcycle use, which undermines the aims of the management work. You get the occasional hothead who advocates stringing wire or rope across tracks. Obviously, an approach which can cause injury or death is unacceptable.
I'm doing the same thing as loggers, but with a positive environmental outcome. I'm also engaged in cycling, which is damaging in some contexts. So I'm not that keen on activists taking things into their own hands, I see no glamour in creating hazards for workers.