Right now, the crime mechanics basically prevent most people from participating.
Yea, most people are carebears, but they might not be if it would not require you to use an alt for every crime, and require you to be able to reproduce that alt in reasonable time.
It is obviously broken, in that even the slightest theft is about as dangerous as an act of murder.
Larceny should become something that is not all too serious, whereas murder should be a last resort, something that you only do if you really mean it, like being really mad at someone, like mad enough to break through several brick walls protected by tons of braziers.
I do not claim to be all knowing about crime mechanics and game design, so take the following ideas only as that, ideas.
If you think they are bad, come up with something better.
Crimes need to be more different in terms of risk/danger.
- Continuing to use the stocks-mechanic, different crimes should have different cost in stocking/releasing and different times that the criminal is stocked.
- TbC should only be viable for more serious crimes.
- Theft should not be summonable at all, if you can reach the leanto of a thief, you can get your stuff back anyways. And if you can't, TbC and kill him does not really help you either. (I know this only applies to "smaller scale" thefts.)
- "Stealing" items that were stolen from your claim/leanto should not be a crime.
- all in all, theft should be not too dangerous, ... waste should be dangerous enough to not break everything you see, ... murder should be outright lethal if you make even a slight mistake whereas making none is no guarantee
About TbF:
It looks a bit broken, that you need to commit crimes to defend yourself.
Without changing the mechanics too much, I would propose the following "fix" for this:
- Under TbF, "fresh" walls that do not yet splash as they are less than a week old, can be attacked without a crime.
(This should apply in the waste claim area and in an area slightly around the TbF.)
This would allow anyone to defend without having to commit crimes in self defense, whereas it would not "break" anything like taking the "protection" of really new players claims.
I mean, building a walled TbF to raid a less than 1 week old claim is probably not that rewarding, whereas you cant tell the age of a wall without breaking it anyways.
And if someone has a 1 week old protected claim near his town that is now used for a TbF, you can at least say he did not pay attention to his surroundings.

About alts:
Alts are bad, hands down.
In conjunction with some balance to crime mechanics, a certain change in the requirements of crimes could encourage people to not simply make/use alts for that.
- Crime skills should require a reasonable amount of other proficiencies, this very well works already for the carrying skills that require (almost) all at a certain level.
- MMori, that is something that really promotes the use of alts, it should be taken out of the game.
Instead of raging on this, I encourage everyone to think of something better instead.

At least, I guess we all can agree that crime mechanics need a little more love.