There seem to be mixed feelings about MyBlogLog, the social networking service that Yahoo bought in January, and the one whose widget you can see in my sidebar, as well as the sidebars on lots of other blogs (it's the one with a row of pictures of different readers who have visited my blog recently). Some people think it's a waste of time and have gotten rid of it, but I think it's actually quite useful - I can see with a glance who has been reading, and I often check out their blogs or their MyBlogLog community as a result.
Like so many other social networking services, however, there is a growing problem with people trying to "game" the system to achieve a variety of spammy ends.
As John Chow and search guru Danny Sullivan have reported, they have been approached to become "co-authors" of other sites - and in some cases were actually made co-authors without agreeing to become so. Robyn Tippins of SleepyBlogger says her husband, a pastor, was added as the co-author of a porn site, which was probably somewhat awkward.