These cases have happened to me twice...
1) Okay so I was on Club Tortimer, and I met this person (We'll call him Bob to protect his identity XD). Bob was Japanese, so it was hard to communicate. In the end, we added each other.
[Time skip]
Afterwards I had a trade going on, then 'Bob' came to my town. He started running around my town, and I was afraid of my flowers being trampled. He stole one of my black tulips from my town, and he was trying to steal my other flowers. I quickly saw this and ended session. I had not given him permission to do so, and he just ran ASAP to take my hard-earned hybrids...
2) This person (We'll call him Jason) was already my friend, I added him from another forum.
'Jason' asked me to open my gates, so I did. He came over and he was holding an axe...He walked up to my Perfect Orange tree and started chopping it down...and took the Perfect Oranges with him...I typed '...' and he responded in; 'Oh sorry' and gave me one Perfect Orange back. It was rotten...And I never gave him permission.
Well, either I'm too soft-centered or people are just mean...
Anyways, sorry for the long drabble, but has this happened to you guys?