Infractions serve as a warning that your account has done something outside of Specktra guidelines. We don't have a complex set of rules, but those we do have we enforce for the continuity and order of the forum. This is a well moderated community and Staff is heavily involved in the forum. It's really a wonderful benefit to you the user and the experience you have while visiting our site.
Oversized images are probably the #1 infraction issued. We have this guideline clearly posted in the FOTD forum and it is also in our set of general forum guidelines.
We won't ban a member for infractions unless it's something extremely excessive and we can no longer babysit the account. Even then it won't be a ban, rather we would suspend the accounts posting privileges.
Banning is reserved for serious abuse or offense and is performed at Administrations discretion, to respect the accounts privacy details are rarely (read never) discussed publically.