Just how many times have they been discovered and destroyed?

It happened Oblivion, and the second time in Skyrim.

More than that, Cicero's journal mentions that every sanctuary in Cyrodiil was put to the sword.

Their so called secrecy and operating in the shadows isn't much to talk about, either. In Oblivion, one of the members comments that the count of Cheydinhal knows the location of their hideout, but is paid and coerced to keep his mouth shut.

And of course, Commander Maro. When you talk to him after killing Astrid, he tells you he already knows where the sanctuary is and even the password. That is ridiculous.

It seems they are rather overrated as an organization.

Not as embarrassing as the Enclave in the Fallout Universe. Now they are pathetic.

at the beginning of Oblivion the Dark brotherhood was actually quite powerful, but Mathieu Bellamont infiltrated the Organization seeking revenge, since the Black-hand was not sure who infiltrated or from where they ordered their Silencers to "purify" the Sanctuary's.. after becoming a Silencer he tricked the CoC into killing the Black Hand by intercepting his Dead-drops, so the CoC and Lucien would take the heat..


the DB in all honesty never recovered from Bellamonts betrayal.. The Black Hand is gone, and the DB has had to forsake the tenets just to stay alive (wonder where the Wrath of Sithis is?)..

Wouldn't Sithis, being a god of some sort, just come up with a way of fixing [censored] again?

I think he dont cares for them

That might be the case.