I agree with a lot of the responses here, this is a really touchy subject.
Firstly, I’ve seen naturalists who have killed organisms while holding/observing them, because of their lack of knowledge on how to handle or observe them properly. They learned from their mistakes though.
I have also seen people, for example, find an injured bird or mammal and try to care for it. This almost never works - wildlife rehab would be better. Unpopular opinion perhaps, but I would leave that bird or mammal alone. When an animal dies, it provides the ecosystem a boost that is crucial to the survival of some chains. If we ‘rescued’ all such cases, it would certainly lead to other species who rely on this, going downhill.
Same here. I used to be a fanatic for catching the lizards and letting them go, but I realized how much stress it causes them. Now I just photograph them and smile at them, and that only.
In similar respects, I see no reason why people pin butterflies and moths. It is purely for personal enjoyment and does not benefit the poor creature at all. Of course, specimens must be taken for scientific reasons, in cases, and this is appropriate. But personal collections are something I don’t really agree with.
I am studying Jumping Spiders, and this occasionally means letting them crawl on my hands. But I would never consider picking them up or touching their abdomen. Both these crimes seem completely innocent, but picking them up could damage their legs or abdomen’s attachment, and touching their abdomens can make the jumping spider ‘rubbed’ - when the hairs that make up their interesting patterns are ripped out by your touching them.
We need to treat the things we see with respect. There is much more fun in observing from afar, rather than infringing on a critter’s stomping grounds. And it’s honest fun, too!