Al Capone going down for tax-evasion didn't require the AG inventing a novel theory of tax-evasion that would have criminalized millions of law-abiding people, and getting a judge to agree with that theory.
Weev does indeed seem to be pretty terrible, but the comparison between the tax-related charges against Capone and the AG's theory of CFAA is not apt.
The AG's theory is that clicking a link, or changing a URL in your browser-bar, is a federal crime for which you should do many, many years' hard time, if what you find after you change the URL or click the link is embarrassing to a big company.
I'll stipulate for the sake of argument that weev may be a criminal, but this is not his crime, and creating jurispridence that makes it into a crime puts people like Aaron Swartz -- and many others, including you and me -- at risk.
What it would do is create enormous prosecutorial discretion: it would turn most Internet users into presumptive criminals. That means if there's someone that the prosecutor didn't like for other reasons, he would be able to threaten his targets with harsh charges and long sentences unless she took a plea (>97% of federal indictments end in a guilty plea).
Who are the most common victims of this kind of prosecutorial intervention? People who are already vulnerable: poor people, people of color, LGBTQ people, etc.
Weev may be a jerk, and he may be a criminal, but if we allow those facts to make bad caselaw, we disporportionately jeopardize the people who are already in the worst position in the justice system.
"Hard cases make bad law."