On bulletin boards and other public internet forums, it is considered rude (like shouting at someone) to type in all caps.

What percent of users consider it rude and I would certainly like a more definite reason than (shouting at someone), which sounds absolutely ridiculous to me.It appears to me that only a handful of users are offended by upper case and I will use lower case when discussing with these people. But the vast majority of users do not seem to care.