We have had them jumped by skateboarders, guys on BMX bikes, and a guy on a motorcycle.
The mom had gone on the page because her 15-year-old son has a keen interest in BMX bicycles.
Among her 612 friends, one of the first listed is a boy named Kyle whose own profile picture shows him airborne on a BMX bike.
1978, semi-acronym from bicycle motocross.
Cross-country bicycle racing
[1980s+; fr bicycle moto-cross, fr motocross, ''cross-country motorcycle racing over a laid-out course,'' fr French moto, ''motorcycle,'' and English cross, ''cross-country'']