No Thieves Guild - a Thief Taker's Guild

It is widely agreed that a 'Thieves Guild' is a ridiculous idea. After all, a guild is a group of tradesmen who have a legally recognized monopoly on a particular segment of the economy. What ruler is going to give a monopoly on stealing things to a bunch of robbers and thieves? They don't want to build a thriving and well-regulated tradition of larceny, they want people to stop stealing from one another. Or at least, stop doing it in ways that the ruler has to do something about, instead of outsourcing it to local organizations.

Thus, my proposed solution: there is no such thing as a 'Thieves Guild'. But there is a 'Guild of Thief-Takers, Watchmen and Guards' which has a monopoly on offering crime-prevention services. You might go to them in order to:

-Hire a bouncer, night watchman or caravan guard to toss out unruly patrons, patrol a warehouse or guard against bandits on the road respectively. The guild provides these burly guildsmen with the necessary equipment, training and moral education necessary to perform their appointed duties without risk of slacking, bribe-taking, cowardice, wenching, gambling or inattentiveness. Not that you have any alternatives, of course: the Guild has its monopoly.

-Pay an annual fee to register your home or business as a secured property, which results in regular patrols each night and a plaque informing would-be thieves that anyone who burgles this address will be beaten within an inch of their lives by the local Thief-Takers, men and women of fearsome repute. The fee is larger, of course, if you sign up only after being stolen from.

-Look through the pile of recovered stolen goods and then pay a small ransom to have whatever property belongs to you returned to your possession. Fees are cheaper if you have proof that it belongs to you, but if you are a good client of the guild and are up to date on all secured property fees, you can report your goods as 'stolen' after discovering their presence at the Guild. If your stolen goods aren't in there, you can leave a description and your deposit on the 'ransom'. Someone will get you once your goods are 'found'.

-Conversely, if you happen to come across some suspected stolen goods, there is a small reward for surrendering them to the Guild. No questions asked on where exactly you got the goods from, as long as there's no reason to think you might be the sort of burglar who goes after up-to-date secured clients. Incidentally, a list of wealthy persons who are and are not secured clients can be obtained for a small fee at any Guild desk. For investor awareness, of course. You wouldn't want to go into business with someone unsecured.

-Place a bounty against a particularly notorious bandit or outlaw. This one isn't even dubiously legal. They'll legitimately go after notorious outlaws to keep their reputation with the Crown from going too horribly crooked.