<p>@Tim is <a href="https://stats.meta.stackexchange.com/questions/5929/question-closed-user-asks-it-again#comment19984_5929">right</a>: users will be automatically banned by the SE system from asking (answering) questions if they have too many posts that are negatively scored, closed, or deleted.  The exact parameters of the ban are not disclosed, even to moderators.  The moderators do not have the ability to impose or lift it.</p>
<p>That said, you don't have to wait for that ban to kick in.  If you see someone reask a closed question, flag it for moderator attention.  We can close it and talk to the OP.  We can also keep an eye on them for a bit.  If they keep posting anyway, we can temporarily prevent them.  It is unlikely this would need to go very far to address the issue.  In truth, we don't want people to get bans.  Those bans are, in effect, permanent.  As I noted above, moderators can't lift them.  So it's better to talk to them and get them on a better track right away.</p>
