Yeah, because Bible studies sit around trying to figure out new and creative ways of slaughtering large numbers of people in one event.
Even if a “Radical Bible Group” isolates teens from their family, (and, admittedly, some aberrant groups do this), the instances of “Radical Bible Groups” actually going out and committing mass-murder are so rare as to be nearly non-existent.
The last mass-murder/suicide by an aberrant “Christian” group could arguably be the Jonestown Massacre, but Jim Jones was actually a Marxist, NOT a Christian, and he abused the Bible.
And that was almost 40 YEARS ago!
Islam is the predominant force in mass-murder these days, and the one or two non-muslem nutcases are the exceptions that prove the rule.