His infamy is due to the particulars of his case and because the hacktivists have latched onto him as a rallying point because of the association with WikiLeaks.
As opposed to, say, the less-visible alleged members of Anonymous and Lulzsec who are likely facing the same exact sort of prosecution 'strategy' as Swartz [2], but because they aren't or are lesser parts of those crowds, no-one's paying much attention. Even though, criminals though they may be, it's just as likely their prosecutors are pursuing their cases with that same lack of justice or proportionality.
[1] in the FOIA sense, not in the piracy sense.
[2] I definitely draw a distinction between Manning and Swartz's prosecutions, as Manning being enlisted, gives the prosecution a distinct ability to go so much further with it.
The only reason we seem to be hearing about Swartz, Manning, the Duke Lacross Team, et al. is that they have a socio-economic standing that most of the victims of this particular brand of "justice" do not.