I sold on eBay for several years. Was a power seller and Top Rated Seller. Mostly sold used electronics that I repaired and would reflow myself. The buyer theft became so bad that I just shut it down and left myself with a garage full of inventory. Buyers would purchase units with expensive components and LCD screens, swap out their broken screen for my good screen and then claim the screen broke during shipping or they they would swap parts such as logic boards, claiming the item was defective, and then make me pay their return shipping plus get a full refund. In the non-electronics stuff I sold, again, more unbelievable fraud and theft. One buyer went so far as to swap out a switch assembly on an antique Kel-lite and then return it because he "changed his mind." I won't even go in to the problems that sellers who offer heavy office or packaging equipment face. They have to eat hundreds of dollars in return shipping costs because a buyer changed his or her mind and no longer wanted the item. That's why you are seeing more and more eBay sellers offering local pickup only.
In a dispute, my experience is eBay always sides with the unhappy buyer. Makes no difference if you have pictures or receipts or anything else. There are a lot of sellers who have gotten hosed on eBay and have had to close up shop leaving big Chinese sellers or big box retailers who can absorb the losses. Fortunately, I have found other selling avenues. It was always just a hobby with me, didn't really need the money, just gave me something to do at night besides watching TV.
Most eBay sellers I know will bend over backward to accommodate buyers. But it is an open air market for buyer fraud.
Electronics are a category rife with fraud on both sides, and in all avenues of commerce beside eBay. There's a lot of reasons for this, some more obvious than others, the biggest being the price tag on this stuff, which makes it profitable to scammers on either side. Anything electronic leaves the seller very vulnerable. Even something mechanical can be risky.
When I used to read through eBay seller forums, the three biggest categories by far that sellers cried over being hurt was electronics, clothing and the like (something where the value is almost completely personal and subjective), and overseas transactions, all consistently at the top. Avoid these, and your exposure will drop dramatically. But...you have to remember that sellers can be liars too (relating to the old salesman's adage, "buyers are liars"), so who knows the real story behind some of these sob stories.
CL is far worse. Years ago I ran a weekend booth at a flea market, and started listing laptops on CL. When I told the buyer they must go to my (public) booth, most tried to come up with some excuse why I had to meet them at a McDonalds or some parking lot, etc. A couple of the excuses were really wild. Reality is, they had evil intentions and did not want to meet me in a public setting. I figured the ratio of thieves to honest buyers was about 11 to 1. Seriously. Electronics.