If I say "with additional research, it may be discovered that there's a correlation between eating corn and various degenerative diseases, and therefor you shou

If I say "with additional research, it may be discovered that there's a correlation between eating corn and various degenerative diseases, and therefor you should not eat corn" with no evidence to support that assertion, it is FUD. Similarly, if I say "with additional research, it may be discovered that WebM infringes on patents, and therefor you should not use it" with no evidence to support that assertion, it is FUD. If a claim is unsupported but used as a criticism of something - especially a reason not to use a product - then it is FUD.