besides hooks OSSN provides a way of storing extra data for you and without touching the database (aka without adding extra columns). Just example (adding/editing):

$user = ossn_user_by_guid(1);
$user->data->extra_attribute_name = 'abc';
$user->save();

Later you can access it via

$user->extra_attribute_name;

I actually built a custom component which records the last ip of each user upon logging in for a project I was doing a while ago (by adding a column to the ossn-users table). It's fairly easy if you understand how hooks work in ossn. You just need to set up a hook for the login event and have it run an update sql query. You can email me about custom development if you want, address is in my profile.

Steven explained my point perfectly

Although I understand and appreciate what has been said about Hosts IP blocking as most if not all hosts CPANELS will have that facility, I think what is being said by Darien is that to block an ip address on the host itself, obviously the IP address must first be known.

If a user of an OSSN site logs in to that site, then the Admins must then first find the IP address, maybe outside of the OSSN site, before the user can be blocked.

If there were an admin component that simply appends the IP address to the OSSN_USERS table when they first register then one could think it would go some way to at least knowing that the admins could then follow any trouble makers with a starting ip address. (Although it is noted that dynamic addresses/shared hosting would be problematic)

OSSN is a very good modular body of work, and for most users, like myself, that do not know php, css or html to any great degree, securing the OSSN website is a priority for any admin, and that would include, naturally, attempting to block any ip addresses that may be "troublesome".

I can therefore understand the views of both the admins of the OSSN sites as well as the OSSN developers (core or components).

If you have ssh access, the easiest (and most comprehensive way to do this) would be to block that ip via /etc/hosts.hosts . deny ... but you haven't told us what kind of hosting you have, so suggestions may be of limited usefulness

I think most hosts allow IP blacklist from the server level. I have blocked certain countries that are most known for hackers via WHM. There is also a way to block anonymous users (proxies). I have been blocked by other sites because I was using a proxy. (Craigslist) Also IP Blacklist cloud offers a free download of the most dangerous IP address. Just remember, the more IP address you add to your blacklist, the longer it will take for your page to load.

Talking about my own experience: You'd hardly win this cat and mouse game in the end.

If someone's goal IS disturbing your site, he would find a way ... using different proxies for example.
Next, you can't rely on someone is entering your site with the same IP all the time anyway. It's quite normal that ISPs shortly drop your internet connection once a day and you'll be back and continue with a different IP afterwards.

Hence, be prepared on doing a lot of manually monitoring until you might find out who is who. In the worst case you have some members who receive their dynamically changing IPs from the same ISP pool - so the bad guy from yesterday may be a good guy today... :)

As Bryce said you have to do via your hosting or server panel.

Further i like to tell you that we are not 24/7 online and when online there are previous tickets to be addressed sending multiple emails will make support more slow. Once we received your email we'll surely reply it and it can take 24 hours at least.

Do you use shared hosting or VPS hosting? This can be done at the server level and block them from hitting your site at all using an IP blacklist. Once you say what kind of hosting it is then it will be easier to direct you