newsletter sign up spamming

[travbacon]

for the past 2 weeks i have been getting spammed with newsletter sign ups. i do not know the reasoning for this as it does nothing but be an annoyance. i can leave it be and just purge them in 90 plus days but still ... see attached screen shots. i did a search and found no other threads like this.

thanks.

[picandnix]

Are they creating accounts or are you using a third party newsletter tool?