It was an inevitable landmark: A Twitter post has become the sole basis for a libel suit. Amanda Bonnen mentioned her "moldy apartment" to her 20 followers, and now her management company is taking her to court.

Horizon Group Management's complaint says the claim of mold is false — though it offers no evidence — and seeks $50,000 plus court costs. Unlike the "first" Twitter libel suit, against Courtney Love, this one involves no other social networking services (the Love suit also involved MySpace postings), and only a single tweet. Our adorable microblogging service is growing up so fast! The offending tweet:

[Chicago Now]