I once broke up with someone over the phone because I could not track him down. He refused to see me in person and I could not find him. He literally kept hiding from me and would not accept my calls. I think he knew I was about to dump him. He thought if he avoided me, I could not dump him. Not being able to find him only made me angrier, so that did not work for him. I dumped him when he finally answered one of my calls again. If he had of answered my calls just a few days sooner, I probably would have given him another chance.
I was also dumped once by a guy via instant messenger. It was really awful because it was Valentine's Day and I really cared about him. What made it even worse was that we worked in the same office. He could have walked into my cubicle and told me in person. What an evil man!