From the Pleasanton Police Nixle Alerts:
The vast majority of bike thefts in Pleasanton take place in apartment complexes and from open residential garages (especially shared garages). A bike thief will use a simple pair of bolt cutters to cut the lock and then ride away on your bike. Here are some tips to secure your bike and help prevent it from being stolen:
Buy the best lock you can afford. U-LOCKS are strong and better ones come with theft warranties. Only buy a U-lock with a flat or disc key. Cylindrical keyed locks are more easily picked.
Always lock through the FRAME AND WHEEL. Add a cable, cable lock, or second U-lock to lock the second wheel.
Lock to a bike rack, or firmly affixed (bolts covered in concrete) parking meter or sign pole - these are the most secure places. Beware of locking your bike to poles that are loosely bolted down and can easily be removed.
ALWAYS lock your bike, even if you're just leaving it for a moment.
Store your bike INSIDE if space is available and lock your bike when keeping it in a garage or on a porch.
REMOVE all detachable items like lights, bags and quick release parts and take them with you.
Record your bike's serial number. Take a photo of you and your unlocked bike. Keep the receipt. This will help you identify the bike if it is recovered by the police.
Learn about the lock manufacturer's warranty and product replacement policy.
Consider registering your bike with the National Bike Registry.
If it's stolen, make sure you file a theft report with the Pleasanton Police Department (925)931-5100.
For more information visit http://www.popcenter.org/problems/bicycle_theft/
or call the Pleasanton Police Departments Crime Prevention Unit at (925)931-5233.