The following data could potentially be cleared, but would make the statistics less usefule, so here are some of the ideas for later:

blank old users that have not been member for longer than 7

• username -> "past member #"
• clear password
• delete profile picture
• clear contact info
• set all membership periods to free
• clear locker

trim data for all users:

• old paymentent entries
• old membership periods
  • can we delete some of that