nearly 1000s of fake registrations/profiles, unsure how this information was spread on huge number of our sites
You are unsure? Here's my guess: Insufficient moderation and/or administration. Should I blame society or myself if the laptop left on the seat of my car is stolen? There is no retaliation
There is no retaliation. What are you going to do, shoot a hoodie-wearing teen for walking past your car? No. There are only common sense measures for slowing them down. Note that I said slowing them down. Just as you can't stop crime, you will never, never, ever stop spam. You can only slow them down. Start by taking away their profile links, taking away their ability to post links. Ban rogue IPs. Ban problematic email domains. Make it near impossible for bots to register. Protecting your site is a daily job
Thousands of fake registrations and profiles is symptomatic of insufficient site administration. Thwarting link droppers, profile builders, and even spammers you never heard of before like reputation management spammers is a daily job. And if you think India is your big problem you are missing thousands more spammers. Day time is when the American, British and Continental European spammers hit. Evening hours are when India and Asia wake up and hit the boards. What time does spam start?
Spam is 24 hours. But if you're going to get your guard up then take note at what times the spam starts hitting your site. If you're on the west coast on Pacific time, 8:30 PM corresponds to 9 AM Mumbai. If you're on East Coast time, then 11:30 PM is the time to step up the IP bannings. But don't forget the daytime spammers from the USA, they're legion.
Don't point fingers at other countries. Take steps to slow down spam:
1. There are scores of spam variations, some devised to go under your radar. You'll be surprised at the lengths they go to avoid detection.
2. Lock down your site against known spam threats and techniques
3. Be aware that the scope of the problem transcends a single country.
Ordinarily I remove all spam complaint posts. This forum category is for discussing how to build links, not to discuss spam fighting. It's in the Forum Charter
[webmasterworld.com]. However you're a long time and respected member and deserve an answer. Hope they were helpful.