With the new ease of name changes? Harder to prove or be certain of. It would depend on it being reported and I would imagine that many members would have a "reasonable doubt" as to whether it was someone attempting to impersonate/mimic or the banned person themselves. The focus now is really on individual posts and the content of them. You may have noticed the change from the old bans (where ALL of the banned account's posts were hidden and returned when the ban expired) to the new bans (where the offending/reported post and/or content is remove permanently, but the other posts of the member account remain visible while they are banned). There are positives and negatives to either/both methods, but the move to the current settings gives me an idea (or at least an indication) of how/what our hosts want bans to represent.