What do you think about link building bots?

[kevinmax]

I worked in both white hat and black hat technologies, used many automatic bots such as xRumer, Scrapebox and other back-link building bots?\
What do you generally think about these automatic scripts? Do you think it is useful for you SEO campaigns?

[kevinmax]

I worked in both white hat and black hat technologies, used many automatic bots such as xRumer, Scrapebox and other back-link building bots?\
What do you generally think about these automatic scripts? Do you think it is useful for you SEO campaigns?