Way back when I first starting using the internet for chatting and instant messaging, I often typed LOL when I thought something was funny. It was akin to a smiley face in my mind. If someone told a good joke, I would respond with LOL. Later on in my chatting career I wanted to find an easy way to say that I had actually laughed out loud, instead of just saying it was funny. I then realized that I had been misusing the acronym that literally meant you had laughed out loud. Since this realization I only use LOL if I have actually laughed out loud at something, but I began to wonder if that was true with others.
If I had misused it, who was to say I wasn’t the only one? This got me to thinking, what about ROFL? I have a hard time believing that someone would actually fall onto the floor because they were laughing so hard, and still have the presence of mind to type ROFL. LMAO is even less believable. If that really happened there would be serious issues to address. If your hindquarters really dropped to the floor because you were laughing so hard, it is very unlikely that you would think to type LMAO.
My conclusion is that there is nothing wrong with using those acronyms, but in an effort to communicate more clearly we should probably redefine them. When someone uses LOL, they probably mean “that was funny.” When they use ROFL they probably mean “that was very funny.” When someone types LMAO, you might want to consider referring them to someone who can help.