I don't worry about it. I lost a bike at a bar in the rain once, but anything else that grew legs I've never even missed. All my stuff is easily removed so it's not hard to get to when I need it.
I've been in commercial building maintenance for 15 years and I've figured out of somebody wants something, it's theirs. I've had people strip 15-ton ACs over the weekend, remove plumbing fixtures from public restrooms, and get into all kinds of places, whether the location held anything of value or not. Don't even get me started on the illusion of security people get from a good door lock.
Securing your CB antenna would be easy. Vaseline isn't going to stay put in the weather and if it gets hot, it'll just drip all over your bumper and make a mess. Just put it on hand tight, and don't leave it on riding around town, just put it on when you need it.