The only difference between Weiner and a hundred other congressmen is either discretion or luck.
If you think what is happening to Weiner has not been orchestrated you are kidding yourself. Sure, he had little discretion here, but like you said, at least 75-100 other congressmen are trolling for sex ever day. Weiner crossed somebody, and they either had the goods on him already or got the goods on him. This thing has been orchestrated.