Michael Brown was at his store in San Francisco early one December evening when his alarm company called. The burglar alarm at his Oakland hills home was going off, and the security company had notified the Oakland Police Department. Brown, the son of former state Assembly Speaker and San Francisco Mayor Willie Brown, was concerned about his wife and three kids. He jumped in his car and raced home -- calling 911 along the way. The dispatcher said police would respond as soon as possible.

When Brown pulled up near his property, he could see burglars in his house. He called 911 again, watching helplessly as the thieves loaded his possessions into a parked car and sped off. OPD arrived five minutes later.

People pay taxes for public safety. They have an expectation that if someone is breaking into their home, a police officer will respond in minutes, not hours. Yet in Oakland, where there are far too few police to deal with the high incidence of violent crime, patrol officers spend most of their time racing from one shooting to the next. The bar for police response has been set so high that someone's life pretty much has to be in imminent danger for a call to be given priority. Even then, depending on what other craziness is going on, officers might not be able to get there right away.

This is why a growing number of neighborhoods that can afford it -- especially in the Oakland hills -- have taken to hiring their own private security to patrol their streets. Even Mayor Jean Quan's Oakmore neighborhood has hired private patrols after an escalation of daytime break-ins.

This isn't just happening in Oakland. In cities all over the country where understaffed police departments are responding to fewer and fewer crimes, frustrated residents are taking their security into their own hands. According to a recent article in the Christian Science Monitor, Oakland joins Atlanta and Detroit, where groups of neighbors are pooling their money to pay for private security. Homeowners associations where residents pay dues ¿have long levied fees to hire private security. But what's different now is that residents who aren't part of official homeowners groups where such costs are mandated are getting together to hire private patrols.

I can certainly understand people doing everything they can to avoid becoming a victim at a time when violent individuals are running unchecked on the streets. I believe private security patrols can be a useful deterrent in some instances. At the very least, they send a strong message that a neighborhood is vigilant. It only makes sense that would-be burglars would be less likely to prey on areas where there is a visible security presence.

Yet the proliferation of private security patrols because government has failed to fulfill its most important function -- providing for the safety of its residents -- is also cause for concern. As budget cutbacks continue to erode public safety services, are we heading to a point where only those who can afford to pay will have any modicum of safety? Where everyone else will be left at the mercy of criminals -- having to rely on the ever-dwindling ranks of police who respond long after an emergency, if at all?

Will public safety go the way of public education in high crime cities? Abandoned altogether by the affluent, who seek out private alternatives?

"Why should Bel Air residents vote for higher taxes to pay for policing throughout Los Angeles, when they can -- and do -- hire private patrols for their own neighborhood?" wrote David A. Sklansky, a professor at UC Berkeley Boalt Law School in Private Police and Democracy. "Private policing easily can become part of the "secession of the successful."

But what almost no one is talking about are the issues of accountability and potential liability with private security patrols.

Armed security guards often carry much of the same equipment as the regular police -- including guns. Yet they are not subjected to the same level of screening, regulatory oversight or training as police officers.

Some security patrols will attempt to arrest and detain suspects until the police arrive, which could place their own lives as well as others' at risk.

Private patrols are no substitute for an adequately staffed, functional police department that responds to citizens in need.

Once you step out of your house, you can't take the patrols with you.

Tammerlin Drummond is a columnist for the Bay Area News Group. Her column runs Tuesday and Sunday. Contact her at tdrummond@bayareanewsgroup.com or follow her at Twitter.com/Tammerlin.