Early this year, DDoS attack size has doubled as a new attack method is being employed. This is called the DDoS reflection and amplification method. This method has the potential to multiply their attack resources by a factor of 500K.
With reflection DDoS attacks such as Memcached, attackers do not need malware to infect and control bots in a botnet. Even unsophisticated attackers can launch an attack. Akamai has observed an increase in scanning to identify vulnerable Memcached servers.
DDoS attacks are likely to occur more frequently in the future. More attackers will abuse Memcached servers to generate DDoS attacks of all sizes. Also, Memcached payloads are being used to deliver extortion messages.
Here is a whitepaper that talks more in depth about how Memcached reflection attacks represent a new era for DDoS.