The way you describe it works is a rumour, in fact we know all about it. There recently was a wave of DDoS attacks on large MTA servers that were hosted by OVH (like most large MTA servers) which was made possible by a flaw in OVH's Anti-DDoS system.
It was fixed by OVH a couple of days ago, as you can see here: http://travaux.ovh.net/?do=details&id=44340
Like i said, we know all about it and have paid great attention to the issue, because there was someone out there (actually a group of people) trying to destroy MTA by targetting important servers with it. So that means we helped these servers and worked in close cooperation to contact OVH support and confirmed that the fix I linked is a direct result of the inquiries to OVH from these MTA servers, after which the server owners confirmed it was fixed and all subsequent attacks failed.
But the situation overall was noticed by many players, because they couldn't play their favourite servers at all times, and they started making up wild theories.
This guy is 1 of them (that has imagination about what happened, but also wants to appear like a tough guy by taking credit for something he just seen happening). For your knownledge, what happened in most cases was players being stuck on joining the server, and otherwise disconnecting suddenly.
Sidenote: the "someone" that was trying to ruin MTA for most players by attacking large servers, has been banned from MTA, along with their entire server and clan (which had great participation in it). Even though I won't mention who they are, I will have to lock this topic to prevent them from coming here and causing a ruckus about it.