Here is a list of things you can do:
1) Temporarily update all of your items to remove anything that might get them banned - yes, I know this will mes up your products for a month, but it is better than loosing them
2) Make sure said items are not visible in the catalog, this may stop sales, but it will help stop the flagging
3) I am hoping that your items are only clearly black market items after trigger words are said...(helps hide them)
4) Change your name + e-mail address of your account at the same time, yes, I know this will cost, but it is the only sure way to run (IMVU has to look you up in the data base somehow, so they will probably use 3 types of info, your name, e-mail, and id), you can not change your id, but changing the other two should throw them off for a while
5) Set your hp to buddies only, shove a bunch of religious stuff on it and join some goody two shoe groups, I have noticed that IMVU tends to ignore you if you look extremely innocent
6) never chat about the black market during an IMVU chat, admin can and will monitor them, here are some nice chat rooms for you:
http://www.freewebs.com/imvumafia/RoomIndex.html
7) we have codes we can add to your hp to crash anyone trying to look at your page without logging and we also have codes to track IMVU staff, PM me for these
8) contact all customers and ask them to keep it hush hush for a while, see number 6, this applies to messages also, IMVU forum PM's are safe if you want them to check their PM box
9) make a fake black market to set IMVU off track, a few guest accounts dressed up to look like black markets never hurt anyone...have friends flag them, let IMVU feel as if they accomplished something
Questions:
1) how many devs do you have
2) how do you normally advertise
3) have they come after you yet?
4) how do you normally display your items?
5) how do customers normally contact you?