Impish Net users have caused havoc again in the US after launching an attack on ETrade and ZDNet. This latest example of mischief-making comes hot on the heals of high profile acts of cyber-vandalism earlier this week against Amazon.com, eBay, Buy.com and CNN. So who's behind it? One report said that paranoid Web watchers blame the CIA. They say the spooks are carrying out these relatively harmless attacks in a bid to put pressure on the US Government to hand over more cash in the up-and coming budget. Other reports claim it is down to disaffected youths just having a laugh. But one anonymous tipster who contacted The Register said corporate stupidity was to blame. "Routers can be set to throttle UDP packets, even small ISPs do it," the note said. "Yahoo, eBay, etc.. were stupid. Echo packets should be turned off. "Corporate idiots should not be in charge when it comes to security. "Stupid. Real Stupid..." he rambled on. ® Related Story Massed hack attack hits major Web sites