You always have to consider the source.
Not all sources are created equal. If I'm evaluating a health issue, I'm far more likely to give weight to advice from a source like Harvard Medical School, the National Institute of Health or the Centers for Disease Contrl than to www.Imaquack.com.
If I'm considering a technical issue, I look for credible sources from the industry and don't even consider individual websites unless they can cite references to credible sources.
Likewise, I discount www.stupidconspiracytheories.com type websites because they're full of crap.