The probability of something like that happening is extremely low. I've done some rather controversial things and many people could have tracked me down, but nothing ever happened. When I opposed Oracle's acquisition of MySQL, a then-Sun employee sent me a nastygram in which one wording might have been meant as a threat (or maybe it was just poorly worded, the guy didn't seem very smart to say the least). That was all.
I've done some work in connection with soccer and many of the people I dealt with there are famous and soccer club officials are from time to time also threatened, but it's hard to find any incident in which anything ever happens, at least in countries in which the rule of law is intact.