Two reports, of a similar nature, from different parts of the country, speculate about the potential for voter fraud. The same organization, Voter Participation Center, is involved. In both cases, people received what appeared to be voter registration documents, but in fact were not.
The documents were cleverly produced, and clearly imply that they are official voter registration forms, requesting significant personal information. But the supplied returned envelope is addressed such that it goes to the VPC, not to voter registration. The relevant reports, with scanned images of the mailings, are at:
This is apparently not illegal, but it is highly unethical, and certainly intrusive. Be aware of any such requests, and check with your registrar if in doubt. If nothing else, you should protect your personal information.