Jailbreaking is still legal regardless of how the phone was purchased/subsidized. The only thing that changed on January 26th was that unlocking without carrier approval is no longer a valid exception to the DMCA, and is now illegal.
Carriers will generally unlock a phone if you are traveling, even if you are within the contract, which makes their own argument about recovering their subsidy hollow. Network locks are unnecessary, anti-competitive, and diminish the resale value of perfectly good used phones.
Either way, I'm pleased that this petition is on course to qualify for a response.