Who uses data manipulation? Governments, businesses (individual or entire industries as we constantly see in martial arts/self-defense), the media, and social organizations with an agenda.

These groups or organizations utilize information to create a narrative on a topic for a specific reason, most often for their own benefit. The data itself could be entirely legitimate and authentic (though it may not be). It's how it's spun that's important, and most people rarely dig deeper and go…

"Hey, wait a minute, that doesn't sound right…."
Remember, data manipulation has multiple benefits, and it's usually very subtle yet sudden. If it fits a person's narrative, they will often support it. Even if it's different from the original source manipulating the data in the first place.

With regards to crime, entities alter information for any number of reasons including:

-create or change a market or push the value of the product (security/arms/training/surveillance)
-alter public opinion (shift-of-perspective/vote-swaying/neighborhood growth)
-reinforce personal/individual message, to play on public emotion (fear/anxiety/paranoia as propaganda)
-create perceived need where there isn't one

Ideas often become beliefs over time and in times of duress

Remember "Inception," the Christopher Nolan movie from a few years ago? "An idea is like a virus. Resilient. Highly contagious. And even the smallest seed of an idea can grow."

We hypothesize and use heuristics to make assumptions about the overall picture to plan accordingly. Even when though a time always comes when those theories, hypotheses, and heuristics need to be verified concretely. It's one thing to have them create a home base for future assessments and to expand on those ideas. It´s quite another to make assumptions and assume they stay forever the same. Eventually, statistics, case studies, and developments clearly dictate they are no longer valid.

So, how is data manipulation done?