Is it not amazing that a Muslim will never eat pork because it is haram (unlawful); never marry his mother or sister because it is also haram, yet that same person has no problem devouring riba (e.g. interest, usury)? Did you know that engaging in riba is a major sin which could lead you to Hell?

“…but whoever returns (to dealing in riba), such are the dwellers of the Fire — they will abide therein.” Quran
(2:275)

Riba is haram in all of its aspects, as the Prophet (peace be upon him) said (Muslim), “Allah has cursed the one who consumes riba, the one who gives it, the one who witnesses over it, and the one who writes down the transaction.”