I read it, mentally, as "diasporastar." It's like if someone types "I <heart symbol> you," I read it as "I heart you," which is cringeworthy.
Do some people not do this?
Also, their URL needs the star, too. Diaspora(asterisk)foundation.org. I just can't stand in consistency. How you do it matters less than being consistent. If you can't put a * in a URL, don't make the asterisk part of your name.
Finally, it made me look for a footnote. That symbol already has a meaning in that context---you can't just re-appropriate symbols to mean whatever you want when they already have an established meaning. I mean, clearly, you can---but it's considered bad form, and for good reasons.
I bet the Diaspora* people are sick and tired of hearing this shit over and over, but you know what? They deserve it.