It depends on the reason and purpose of multiple accounts.
If they are proven to have been used for nefarious or malicious purposes then it's probably a ban.
One account set up to game the download limits will simply be deleted, further vexatious and continuing creations of accounts will mean a ban.
Old accounts that people have genuinely forgotten about but are still active, or new accounts that users set up because they forget passwords, should generally be merged. If someone has an account access problem they should have used the reset facility or contacted me before they created a new one...
Long story short, in an ideal world no one should have more than one live account.
Fair point there mate