Janell Burley Hofmann honored her 13-year-old son’s “maturity and growth” at Christmas with his first iPhone, but it came with strings attached.

Eighteen strings, to be exact, in a written code of conduct that placed the mommy blogger at the center of the debate over how parents should handle technology in the hands of their teens, especially younger ones just entering the frenetic world of social networks and smartphones.

Thousands of people, including those bemoaning too much helicopter parenting, commented and shared the funny, heartfelt agreement posted at the holiday by the Cape Cod, Mass., mom of five. The interest crashed her website and led her to appear with her eldest, Gregory, on morning TV.