There are two implications here I'm not entirely certain of.
The first is that enforcing laws is not a "similar purpose" as above.
The second is that the government soliciting volunteers to perform a task constitutes no longer considering that task a function of government.
In the modern context, I don't think there's necessarily a principled distinction. The Long Beach city government is probably being pretty smart. Still, in a historical context, this is a big change. In the English-speaking world, standing national armies are relatively new, and government-paid firefighters and police forces are even newer. But employees of the state (or the king) have been prosecuting crimes since (checking Wikipedia)...at least 1243 .
If you have graphic design experience, check out the on-going logo design competition at 99designs for the Singularity Institute. There are still 6 days left to enter and be eligible to win the $295 prize if your design is selected. Tell your friends with graphic design experience too. There are very few submissions currently.
Note: This is a blind contest. Designers can only see their own entries. All designs will be revealed when the contest ends.
If you're interested at getting a peek at the designs, they will be online after the competition is over. This is standard practice in 99designs contests to prevent designers from contaminating each other and having all the designs drift in a certain direction.