Feedly and Evernote, two popular IT companies were attacked by Distributed Denial of Service (DDoS) successively. It caused temporal dysfunction of these services.
BBC News Technology: Feedly and Evernote struck by denial of service cyber-attacks
Feedly reported that it was blackmailed by a cracker to send money for cancellation of the interference. It refused the demand of the cracker.
Blog Feedly.com: Denial of service attack [Neutralized]
DDoS is a method to negate a server with sending numerous requests simultaneously via the internet. If the amount of cues overrides the capacity of the server, it is paralyzed because it cannot respond to all of them immediately. This kind of attacks is usually performed by controlling illegally a lot of PCs possessed by other people.
According to this article, the majority of companies have experience of being attacked by DDoS in the last year.
Forbes: Evernote Pounded By Aggressive Cyber Attack
I know that DDoS attack, but not it frequently occurs. Companies are always struggling to defend themselves from IT criminals. In these cases, Feedly and Evernote rejected the coercion of the criminals. However, other companies accept paying money to the crackers, I guess.
Cyber attacks were born with some computer viruses only a few decades ago. Nowadays, there are many contributions of cyber crimes. In Japan, the police was tricked by a criminal, disable to avoid arresting some innocent persons, as I referred. Innovative solutions are expected in this region.