Deceptive trade? Care to share your story?

I remember on GTS negotiations I would always find someone wanting to trade me a lv 100 shiny porygon-z. It was like someone was hacking a bunch of them then trading it to people then those people would try to trade it.

When I was like, 12 or 13, I got into a discussion about shinies with someone in an IRC room. I mentioned that I had a shiny Ninjask and Shedinja, and the guy asked if he could borrow them to clone, so that we could both have them. I've personally never had anything against cloned Pokemon, and I was naive and overly trusting, so I agreed. He ran off with both and never gave them back.

when i was 6 and my brother was 11, i just started playing ruby. he had been playing sapphire for a few years, and he almost completed his perfect team, while i was trying to figure out how to throw a pokeball. Anyway, i used rock smash on one of the rocks outside of mauville city and ran into a geodude. this was my fourth pokemon (my team was marshtomp, silcoon, and ralts), two gyms later, it was a graveler, and it was the powerhouse of my team. At the time, i was really naive about pokemon and my brother convinced me to trade him the graveler, because he said "it will make it learn a secret move". Of course, it evolved into a golem, and i got an egg that hatched into a tentacool.

I actually had the opposite of this problem. Someone was trading me a bunch of legends I didn't have yet in exchange for masterballs and rare berries. I went and checked them afterwards and 3 were shiny. Thank you random pokemon trader!

I once made a deal with someone on an animal crossing forum; I agreed to exchange with them 50 hybrid flowers per legendary pokemon (it added up to around 2,000 flowers.)

What did I get? A boat load of hacked shiny legandary pokemon. I was so dissapointed too because there was a mew in there which I was so excited about getting :(

Once someone convinced me to trade a shiny for a "rare" Pokémon egg. I know, i know, taking it was a rookie mistake. The shiny was a hack (from someone else) I was going to get rid of anyway, so I thought why not. I literally kept tue egg in my team for days and it did not hatch or show any progress, and it didn't respond to treatment from my base grunts. I eventually found out how to get rid of it, really, I am quite stupid for even trusting the person.

I was just thinking about my experience with this today. Back when I was still in elementary school, me and my friends at the time were clocking in dozens of hours into Pokemon Diamond and Pearl (the newest games during that time). Going through my boxes of Pokemon that I migrated from my Fire Red Version, I realized I had a shiny Arcanine. I recall catching it as a Growlithe in the Pokemon Mansion on Cinnabar Island before I even knew what shiny Pokemon were. One of my best friends at the time was in a phase where he was really into dogs, and Arcanine was always his favorite Pokemon. He offered me a shiny Entei he got out of the GTS. Being suspicious of its legitimacy I asked him to confirm it was a legit Pokemon. He said it was, but one thing me and my friends did a lot was "no trade backs" to ensure we keep the Pokemon we really wanted, and this was one of those instances. I accepted the deal only to find out moments after that it was captured in one of those areas in Sinnoh only available after defeating the Elite Four. Well played elementary school friend.
That was my only shiny Pokemon I ever caught up until yesterday, where I caught a shiny Feebas and now today a shiny Wailmer.