Watching crime in apps or website By watching crime in mobile apps or in website , is one actually participating in the incident? If one thinks about it, is one perpetuating the incident again? Does it add to one's karma? How does one react to this kind of situation ? if we ignore the video , are we creating a bigger incident?

Regards.
Let's separate this out. If you watch a recording of a crime on a website, does it impact the victim of the crime? Not in itself.

It DOES give a "view" to the video, and thus you are, in a sense, giving your tacit support to the recording, and publishing, of the event. THAT is, for me, the reason not to watch such events, as far as the world impact is concerned. I guess one needs to attempt to assess the motive of the publisher - was it to shock? Or to educate?

As far as impact upon oneself is concerned, this is another question. Are we adding to our own karma? It depends entirely upon the intent with which we are watching. Sooooo much consumption of internet material is quietly mindless - which means we are blindly watching with no concern for what impact it might have on us: because someone has published it, it must be okay. This attitude allows others to have control over our minds! As a meditator, I'd rather that weren't the case!

Thinking about karma is tough - does it affect my Karma? Can I ever experience my karma as a tangible sensation? I'm not sure I ever have.

Can I see impacts on my experience that demonstrate that certain kinds of actions have noticeable impacts on my experience? For sure, and some have impacts on my experience in meditation. Some I can learn to work with. For others, I just practice "guarding the gates of the senses" and avoid that stimulus.