Going through my campaign notes in preparation for Lure of the Expanse when I found a message one of the Arch-Militants left pinned to the remains of the command throne on a raider they burned:
Dear Karrad Vall,
I have destroyed this ship and killed Captain Robert.
If I see you or any of your pirate scum in my space again, I will crush you like a bug!
Love, Boris Reznov
PS: I have your stuff.
In character, none of the other PCs know about this, and Boris, bless his Vostroyan heart, is not from round these parts, and so doesn't know of Vall's reputation in the Expanse. In fairness, he did burn the ship almost single-handedly (led a boarding team with a lot of explosives and incendiaries, and ordered them to burn a hole to the bridge). And he did loot several crates of high value stuff (once the fires had gutted the ship)- including a couple of arm-rings made of a greenish-black onyx with certain runes on them, and a glaive, apparently made of titanium, but somehow covered in …rust?
Unfortunately, the PCs were flying in a wee little sloop, and the raider they burned was not alone (and managed to get away scot-free).
Cut to roughly a year later (they had some bad warp runs), and the PCs have just been to the Cell to here the Witches' Foretelling. What did they bid? One of Vall's arm-rings (after having it identified as probably xenos, definitely pre-Imperium, possibly pre-human; with the only description coming from a kinebrach archaeology text: "…and He who wears it will be cursed with Life Everlasting, His Body perfect and incorruptible…" with the other one getting the description "…and from Him shall flow the Breath of Life. Where He walks, seeds sown shall sprout, where He touches, all shall be ready to be reapéd…").
To make matters worse, the PCs decided that they needed to outfit their new ship (a Repulsive Grand Cruiser, with many launch bays) ASAP before setting off, so Boris and two of the other PCs decide Money Is No Object, and burn the equivalent of Apple's gross annual income in Profit Factor, making sure everyone on Footfall knows their names, and the ships they're on, and have at least a clue about their quest…
Not asking for suggestions on how to mess with them (although they wouldn't be unwelcome), just raising it as an example dumb decisions…