Thankfully I haven't (yet - knock wood) had any incidents related to lost basses - though I've been through a few bungled deals that eventually sorted themselves out thanks to a highly skilled local luthier who saved my bacon twice!
But - in the interest of telling a real - true story, back in 2011 I had a very valuable, hand made mandolin absconded with. I won't talk exact value - but it cost me essentially the same $ as a high end Alembic bass.
I had just completed my 3rd bluegrass set with my band at a small annual festival in Plymouth, CA - an obscure little town 40 miles SE of Sacramento near the Cosumnes River and the Amador / El Dorado county line.
I split the festival in my Volvo having loaded this mandolin in a white Calton Case as well as a Martin HD28, a German plywood double bass - my camping gear and a laptop computer.
The weather was hot so I headed East instead of West with the intention of getting in a quick dip in the previously mentioned Cosumnes River.
I parked on the side of the road in Fiddletown near the river but it wasn't till after my swim that I realized I'd left my rear passenger side window cracked about a 1/2 an inch.
When I got to the river I found three 20 something kids smoking. I asked them if there was a better place to dive into the river and they pointed upstream - so I hoofed it about a 1/4 mile further - took a dip and then headed back to my car...
....only to find my security system triggered and a dashboard message stating "security breach - check vehicle."
It took about 5 seconds to sum up what had happened - the thief had eyeballed my car - spied the cracked window, and noticed the easily snatchable Calton case. So he grabbed what he could - probably with an intention to take more but the alarm on this car is notably loud - but not loud enough for me to hear it a quarter or a mile up a river.
When I calmed down, I immediately contacted my pals at Mandolincafe.com - a site that gets thousands of hits a day and that maintains a stolen instrument registry.
I then called the El Dorado County Sheriff and filed a police report.
When I got home I wrote a thorough description with serial number and explanation of the incident and posted it everywhere I could online - Mandolin Cafe, Facebook, any stolen instrument registries I could find and I emailed it to dozens of music stores all over the West. I checked CL constantly in the Bay, Reno, LV, Portland, Sacto wherever I could.
Exactly one month from the date of theft, while driving through Golden Gate Park en route to work in Marin, my cell rang and a friendly voice explained that he'd just found a beautiful A. Lawrence Smart Mandolin being sold for an implausibly low price at Skip's Music on Auburn Blvd in Sacramento. The caller was slightly glum when he said - "I put a deposit on this instrument, took note of the serial number and then went home and googled it. Then I realized I couldn't own this thing, cause it's your stolen mandolin!"
After that call I contacted the El Dorado County Sheriff and the dominoes began to fall.
The Sheriff visited Skip's music and found out the thief sold the instrument to a "fence," who in turn traded the mandolin for a Marshall amp and $1000 at Skip's - and that apparently Skip's did zero in the way of due diligence to find out the provenance of my mandolin.
The Sheriff obtained 411 on the Fence - forced him to cough up and return the amp and $ to Skip's and to rat out the thief who (surprise, surprise) turned out to be one of the three kids I'd first met at the river.
I eventually arranged to meet the Sheriff at a Peet's Coffee at the Nut Tree in Vacaville and got my mandolin back after 5 weeks! I still play it - frequently, and am way more careful with it and all my other instruments.
Per the El Dorado Sheriff - both the thief and the fence received felonies!
This one didn't get away!