• Is a sign like this one likely to discourage thieves from breaking into your car or truck? Some Reddit users who park their vehicles on San Francisco streets say it does. (Photo used with permission of Reddit user Cyberpatrolunit.) Photo: Cyberpatrolunit/Reddit
Photo: Cyberpatrolunit/Reddit
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Other California cities made it onto the "hot spot" list:

22. Visalia-Porterville area

2,108 thefts
458.4 thefts per 100,000 people
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Is a sign like this one likely to discourage thieves from breaking into your car or truck? Some Reddit users who park their vehicles on San Francisco streets say it does. (Photo used with permission of Reddit user Cyberpatrolunit.)
The hope, of course, is that a thief will read the notice and decide: "Huh. No valuables in this one.I guess I'll break into some other car."
On Tuesday, a Reddit user posted a photo of such a sign and posed the question "Do you think it works?" to the Reddit community. A lively debate ensued.
"Sounds a lot like something that someone with valuables in their car would say," wrote a skeptical Maddox83a.
But iamthewaffler disagreed, citing personal experience.
"It's strong signaling that works VERY well," the commenter wrote. "The intended victim for thefts from cars are people who are from out of town, other "safer" parts of SF, etc who don't know that certain areas are very prone to car break-ins. If you have bothered to print out a sign and put it in your window, that shows you know exactly what neighborhood you're in and the chances of anything valuable being in your car are extremely low.
"These are crimes of opportunity, and if you simply let the would-be thief know that you're from this part of town and aware of the danger, they'll pass right by.
 
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"Source: my BMW was broken into 6-8 times in 2011-2013 in my neighborhood where I parked it nightly, and has been broken into zero times since 2013 when I started putting a sign in my window."
Several people on the thread had their doubts.
"Maybe they just know your car by now. ;)," cracked timewast3r.
One thing for sure, car break-ins are no joke in San Francisco.
About 85 vehicles are reported to have been broken into every day in the city, according to SFPD data for this year. That includes only cars whose owners reported the crime. The actual figure is doubtlessly higher.

This year a total of 17,970 vehicle break-ins were reported from Jan. 1 to July 31, a 28 percent increase over the same period in 2016. In August, a police shakeup eliminated a citywide task force focused on the epidemic in favor of assigning dozens more cops to walk neighborhood beats.
The effectiveness of that measure has yet to be determined.
A few Reddit users suggested that car owners forget about the sign and simply leave the car doors unlocked. But that prompted stories of homeless people sleeping in vehicles overnight, doing drugs and/or having sex in them, and even using backseats as a toilet.
Other recommendations included:
—Leaving your car a mess inside and out to discourage thieves. Place cardboard over floor carpeting or leave storage boxes of junk on top of seats folded down.
—Leave the glove compartment and center consoles open (take the bulb out if the glovebox light stays on).
—Get rid of your car and just use Lyft, Uber and BART.
One Reddit user said he had tried the sign ploy with no success. He wrote that his vehicle had been burglarized 10 times in the past 30 months. We reached out to the San Francisco Police Department for opinions on these methods, but had not heard back by the time of publication. 
William Gee, an insurance agent with AAA in San Francisco, said the best protection against break-ins is to carry comprehensive coverage with a low deductible — $50 or $100 — even on older cars that don't have collision insurance. He noted that making a comprehensive claim, say on a broken window, would not raise your premium as a collision claim would.
But Reddit user design_1987 says the sign is the way to go. 
"This works imo. I've seen vehicles in my neighborhood with (the) signs remain untouched for years while others get broken into right next to theirs. Saw this happen a few times so from my own personal experience it seems to be working. Again, its not a guarantee!"