Thanks +Enrico Altavilla
. I thought it was clear, I was joking since those very long querystrings suggest nothing good.
But you make me understand I wasn't clear at all.
Excuse me +Dinesh Arulmani
It was a bad joke.
My advice is to ignore them since they look to be something spammy. Seldom, but very seldom, you could collect a backlink from 404, but only if is from a website which share topics with yours, and from good contents. For me happened just a couple of time.
You can read a more official opinion from +John Mueller
herehttps://plus.google.com/+JohnMueller/posts/RMjFPCSs5fmThere’s no need to “fix” crawl errors on your website. Finding 404’s is normal and expected of a healthy, well-configured website. If you have an equivalent new URL, then redirecting to it is a good practice. Otherwise, you should not create fake content, you should not redirect to your homepage, you shouldn’t robots.txt disallow those URLs -- all of these things make it harder for us to recognize your site’s structure and process it properly.