The 'C-box' as it's called contains popups, Ads and malicious coding is sometimes contained in the Ads. . .But, this is only if you use the free c-box. But, either way you risk losing members and hits on your Website\Forum by using this code. . .Besides the extra load time, The c-box literally calls for trolls\spammers to cause havoc in it.
I recommend staying far away from this Widget as possible.
Cbox is adware, for it displays ads on the free cbox according to the country you live in, without mention of it in the terms and conditions. Such ads are also irremovable unless you purchase the premium cbox.