Abuse against IPv6 transition technologies

Some of these can be used as "open relay" of packets
Malicious parties can take advantage of these
Some of these can be used to bypass access control

Possible abuse
ipngwg: RFC2553
ngtrans: RFC1933/mech-04, 6to4-04
(maybe more - need your help)
Solutions/protocol fixes
Integrate into the original specification, or
Publish the i-d as separate RFC as "suggestions to implementers"
Recommendations

I'm NOT criticizing, nor trying to delay deployment
Would like to fix the issues, before these get used by bad guys