I personally don't think the carrier makes a bit of difference. You can do some searches here or on Google and find plenty of people who have had stuff stolen from suitcases in South Africa, primarily at JNB. Now having said that, I nor my traveling companion have had anything stolen but I will account that to luck more than the fact that the risk is gone. Supposedly they did change the contractor at JNB a couple years back since that's who they blamed the problem on but I don't trust that myself, it's the same labor pool these guys hire from.

For the floridagal23, probably the best you can do is make sure you have a lock on your zippers since many overseas airports don't have plastic wrapping. If you do have something of value that you must pack in the checked bag, then a trip to Tesco/ASDA and buying the widest plastic wrap you can and doing it yourself would be better.

There have been 4 times my luggage has transited JNB without issue when I could not get plastic wrap, once because I didn't have enough spare time on arrival for check in, another because my outbound flight at CPT was earlier than the wrappers opened, and others have been because I originated in countries that didn't have it. Usually all I've had for the taking was clothing anyway, but one time it was full of diving gear that I was very nervous about. I did use locks, but I don't think that does much good in SA. Like I said though, I've been lucky, so you all may be too but if it does happen then your stuff is gone with little to no hope of recovery even if you catch it right away. To make it worse are the absurd carry on rules in SA, so trying to protect your luggage by keeping it with you is impossible, it's almost as if the airport authority and thieves are in cahoots on this.