The internet is a series of branches, and atheists want to send their beliefs down those branches, and into your child's bedroom.
No more so than the religious nut jobs. How many times have you browsed to a site thinking it to be a legitimate news site or scientific article only to find that it was a well disguised religious message.
Real religious belief requires blind faith, if someone loses their religion because of the wealth of information on the internet that refutes their belief system then they were clearly lacking in the faith department.
I went from agnostic to atheist after the death of my mother! long before the rise of the internet as we now know it.