Removing my real name from activities?

When I registered for Hashtags.org, I used my real name, thinking that when I posted an activity, my username would be used. When I posted however I found out that my real name was used. For privacy purposes I would rather my real name not be used, and so I edited my profile to reflect my username as my “name”. That worked, but it did not change my name in activities, which still reflects my real name. Can this be changed or deleted? Please help.