Hi,

Whois seems to say it's Charter Communications, abuse@charter.net.
But if I mail them, they say:

This email address is for reporting incidents of abuse coming from IP
addresses registered to Charter Communications.  Abuse from IP addresses
not registered to Charter Communications should be directed to the
registered owners of the IP address in question.

The following link should be of assistance in locating the organization
responsible for the IP address:

    http://www.arin.net/whois


Thank you,

Charter High-Speed Internet Security Team

# # #

From: Olaf van der Spek <olafvdspek@gmail.com>
To: abuse@charter.net
Date: Tue, 25 Jun 2013 09:11:38 +0200
Subject: DDoS Attack from 24.205.98.101

--
Olaf