NEW YORK (AP) — The attempted attack on a provocative cartoon contest in Texas appears to reflect a scenario that has long troubled national security officials: a do-it-yourself terror plot, inspired by the Islamic State extremist group and facilitated through the ease of social media. Terrorism experts say the spread of social media, and savvy use of it by extremist groups, has facilitated a new wave of relatively small-scale plots that are potentially easy to carry out and harder for law enforcement to anticipate. While plots orchestrated by al-Qaida have historically involved grandiose plans designed to yield mass carnage — including airline bombings or attacks on transportation systems — the Islamic State group has endorsed less ambitious efforts that its leaders say can have the same terrorizing effect. U.S.