In one of the first strikes, a flood of junk messages was thrown at the e-mail server of the Parliament, shutting it down.
The addition of words that typically do not appear in junk messages can sometimes allow the spam to slip by the filter.
The junk messages overwhelmed the services, slowing them, and in the case of Twitter and LiveJournal, shutting them down entirely for a time.
Cohen had spam filters that diverted junk messages from his correspondence, but he still received almost a thousand e-mails every business day.
In a denial of service attack, one computer is programmed to flood another with junk messages that slow down the machine's performance and block legitimate users.
By limiting Inbox-bound traffic to messages from people you actually know (and people who've paid a dollar), Facebook can better ensure that you'll never see junk messages there.
As such, to tune its spam filters, Gmail has relied heavily on user reports of junk messages, which are made by clicking the box next to the offending communication and then clicking 'Report Spam.
During the assault — the latest eruption in a yearlong skirmish between nationalistic hackers in Russia and Georgia — unidentified attackers sent millions of spam e-mail messages and bombarded Twitter, Facebook and other services with junk messages.
No matter how recent the spam filter, a few junk messages are likely to sneak through your mailbox defenses amid the battle of programming wits between those who send spam and those who write software to block it.
Advances in spam-catching techniques mean that most computer users no longer face the paralyzing crush of junk messages that began threatening the very utility of e-mail communications just a few years ago.
