Lord Winter- i'm sorry to see that You've obviously been exposed to some pretty bad behaviour. i however don't feel that it's particularly widespread- at least with the collared subs/slaves i regularly interact with. i, like a lot of submissives, like to joke around with friends here, be they Dominant or otherwise, but i'd rather gouge out an unspecified body part than to disrespect my Master or indeed any of my friends.
We all learn through repeated meetings with others online (or otherwise) what is an acceptable standard of behaviour around that particular person. i dearly hope that all that's happened is that somebody's overstepped what they thought was acceptable or that it's been interpreted that way. i don't know of any submissive, online or no, who would knowingly portray their Dominant in the ways You've described.