Isn't spamming the whole blockchain possible since its public?

[dannotestein]

Keyhotte is a desperately needed now.  But as I was thinking it over, couldn't someone if they were sinister enough (or wanted free adveristing) just do a scan of all the ID's  (or public key) created on the blockchain and send them mass emails? 

Do I have this wrong, or are there any safeguards in the works to prevent this?

Keyhotee will require proof-of-work for sending broadcast messages to non-authorized friends, hence making it costly in terms of CPU power to spam (with an additional cost for each recipient added to the message). It will also support "cpu cheaper" messaging between friends.

[Pheonike]

Charge them a transactions fee for a number of simultaneous mails. If they want to spam, we can at least get paid for it.

[Pixar]

Keyhotte is a desperately needed now.  But as I was thinking it over, couldn't someone if they were sinister enough (or wanted free adveristing) just do a scan of all the ID's  (or public key) created on the blockchain and send them mass emails? 

Do I have this wrong, or are there any safeguards in the works to prevent this?