Russian Mob
The big bad wolves in the world of cybercrime, Russian mobsters control a huge hunk of the identity theft and fraud black market. Access to tokens that would get them more easily into banking and financial industry systems would further fuel their profitable enterprises.
China
When government types talk about cyberwarfare threats, the "with China" is often implied. Our governments have been playing a cyber intelligence game of cat and mouse with China for years and access to the SecurID tokens that the Department of Homeland Security depends on so heavily would give Chinese hackers an edge.
Iran
China isn’t the only foreign state looking to wreak damage from afar, though. Iran also has an active hacking contingent and that country’s leadership has been unequivocal about their distaste for America.
Anonymous
With an axe to grind against the same type of government and corporate entities that use SecurID to protect their assets, it’s not entirely out of the realm of possibility for some members of this rag-tag group to go after the tokens to embarrass these organizations.
Corporate Spies
Even if many of the consultants who help their clients fend off and deal with competitors can’t disclose much, they all agree that corporate espionage is alive and well these days. Depending on the objective of a corporate spy, the gaming of SecurID could get them untraceable access to high-value systems.
Malware Kit Developer
These days there a many black hat developers who create automated malware kits that allow non-techie criminals to perpetrate attacks and subsequent fraud. A malware kit developer with the SecurID goods could create even more powerful kits.
Terrorist Hackers
Token information that would allow a terrorist to authenticate as a "real" user within, say, a nuclear power plant’s remote access systems would be valuable information to perpetrate sabotage.