[peel40]

I don't know about the current query size limit but I think it's pretty likely to get hit quickly as you correctly pointed out. But, it's useful to use the wildcard "-site" ex: "-site:bigwebsite.com" for excluding just the site, and not the very word being mentioned.

ex:

facebook censorship -site:facebook.com

https://www.google.com/search?q=facebook+censorship+-site%3A...