Just been checking my backlinks on GWT.
Quite a few that are listed on places like Open Site Explorer and ahrefs don't show up in GWT - most noticeably the pr0n sites.

Why is there this discrepancy in reports between the tools like OSE/ahrefs and GWT?

I'm pretty sure that this 'collection' of links is the work of a competitor.
The wedding photography market is rather competitive and there's some very underhanded things that go on, both online and offline (like putting other peoples sample albums in the bin at venues etc etc).

They first appeared around the same time I dipped into the top 10 for my main keyword. I don't remember specifically who was in the top 10 back then, but none of them are now.

I can well imagine someone desperate who was either trying to rank up there, or trying to stay up there, going on Fivrr and buying a ton of links. At one point there were over 5000 spammy links. Before that I had about 200 odd. You can see the peak in ahrefs. Thankfully because they are crappy links, most of them have died naturally.

Thank you to everyone in this thread whose shed some light on the issue and offered solutions.

Thank you Robert.
I'll find a request removal template (know any good ones?), and get cracking on that.
Hopefully it'll improve my exposure in the SERP's as I'm hovering just outside the top ten for most of my targeted KW's.
I'm sure I know the answer to this (which is, no), but is there anyway to prevent this sort of digital sabotage happening in the future? Or at the very least stop it negatively effecting my site?

Alex

Edit - I see Luke has answered in response the second part of my reply while I was typing.

Last year I noticed that overnight my site was backlinked by 1000's of spammy links.
All with same anchor text and all really awful unrelated sites (law, money, mobile phone, pr0n sites, etc).

I've not been hit with any penalties (or at least been messaged with anything to that effect), and I still float around top 10 for that anchor text, but I don't like having 1000's of spammy links with exact anchor text pointing to my site. Especially when all the other competitors have a fraction of the number of links.

What would be the best way to combat these links before they do serious damage to my rankings.
If you want to see for yourself, the site is www.alexkilbeephotography.co.uk

Thanks in advance.

Just been checking my backlinks on GWT.
Quite a few that are listed on places like Open Site Explorer and ahrefs don't show up in GWT - most noticeably the pr0n sites.

Why is there this discrepancy in reports between the tools like OSE/ahrefs and GWT?