Without directly quoting from the text, give me a summary of the second home controversy in Gwynedd, Wales.

By the end of 2001, as much as a third of the homes in the Gwynedd county was owned by owners not using these houses as a primary home. The local community was concerned that the use of the Welsh language was at risk because a growing amount of owners did only speak English, not Welsh. To combat this phenomenon, two national parks in the county started limiting second home ownership in the area, requiring proof of local need or strong ties in the area.