As is often the case, Zynga (ZNGA -7.6%) is falling in sympathy with Facebook. Shares are once more flirting with the $3 level. Some other recent consumer Internet IPOs also aren't faring well. GRPN -3.4%. YELP -4.7%. ANGI -2.6%. Neither, for that matter, is Chinese social networking site Renren (RENN -4.3%).