So, a few years back, I joined a game that was advertised in a Discord server I was in. The party consisted of my Dragonborn Cleric, a Halfling Bard, a Kobold Fighter, a Lynel (yes, from Legend of Zelda, but that's a whole other can of worms) Barbarian, and the aforementioned Drow Rogue. He was clearly TRYING to be a subversion of the edgy loner type rogue, being fairly social and personable, but he very quickly showed that was just a way to try and get away with being just the worst asshole.

This player was very much of the mindset that anything he did was fair game as long as it was "what his character would do", and he constantly made things harder for us as a result. Be it constantly going behind the party's back and only doing things via DMs with the DM, having no filter on extremely sensitive information, or just generally being unpleasant enough to cause the Bard's player to leave the game MULTIPLE TIMES. I don't blame the DM for this, as it was his first time running, and was learning to grow more assertive as the game went on.

This was a case where the most minor infraction I can remember is the time he secretly spent party funds to replace a broken window at the tavern we were staying at at the time, which sounds nice on paper, but what he got was a tacky, overdesigned, and expensive stained glass piece, for a rowdy bar where brawls and broken windows are a near daily occurrence. The owner, who did not even ask for his help, was less than amused and shattered it on the spot.

As for him being fast and loose with sensitive information, I can think of two specific examples. The first is when the party paid a visit to the town's criminal underbelly. We were, very justifiably, sworn to secrecy on the guild's location and operations. He loudly spilt the beans about our meeting almost immediately. The second was when the Bard's player came back to try things again with a new character, a Goblin Warlock. Goblins were under very heavy prejudice in this city, so she really wanted to keep her identity very secret, but told us as a gesture of trust. The Rogue deliberately blurts out her secret in the middle of a crowded street, much to her terror, and the player's frustration.

The absolute worst of it, was when he decided he wanted to investigate the city at night to learn more about the current plot point. My Cleric and the Warlock are both pissed at him at this point for multiple reasons, so we say we don't want to. This fucking guy decides to use Disguise Self to make himself look like MY character to try and trick the Warlock into joining, even though I was just vehemently against the plan not five minutes ago. This was the final straw, he didn't tell me he was going to do this, let alone ask if it was okay, and myself and the Warlock's player both called him out on how this was beyond uncool, ending the session early with me leaving the call, and the Warlock leaving the server for the second time.

The straw that broke the camel's back happened the next session, when he and the Fighter did the investigation. I was finally sick of his shit to the point that I didn't attend that session.

So the Cleric and the Warlock are not here but the other two (the Barbarian had already been kicked out at this point) wanna go explore the city.

The Rogue is really really sure the other players will be ok with him taking their gold coins. Our Fighter, who is a glorified cockfighting rooster, has been carving his way through everything that dared to piss him off is the one going "......mhhh maybe we just ask for one of those healing potions. I think that's prolly enough right"

And the Rogue keeps pushing and is about to start attempting to steal from a PC who isn't even at the table.

After multiple times of the DM trying to push him away from that course of action, he finally puts his foot down and has to outright tell him to knock it off. Before the next week had rolled around, that player was kicked from the game, and our Bard/Warlock returned permanently this time, now playing a Wizard. The Fighter brought one of his friends on to fill the vacancy and it quickly became a highlight of all our weeks, especially when we paid another visit to the Thieve's Guild, only to find the corpse of a certain Drow Rogue strung up as an example for anyone who might think about getting loose lipped like he did. He fucked around, he found out.