In as far as open source is concerned, the IP issues have mainly been in copyright and patent. While this is not directly open source, it may affect any one who uses domain names as part of their trade mark or if you use a name that is similar to someone else's registered Trademark that has a generic name that ends with .com or .org.
๐๐ฎ๐ฐ๐ธ๐ด๐ฟ๐ผ๐๐ป๐ฑ The word Booking is considered generic. Because of an old ruling (https://www.law.cornell.edu/supremecourt/text/128/598) names that describe a class of goods cannot be trademarked even if you add Co at the end. The word "booking" can be seen as the class of what Booking.com does. Just appending ".com" should not make it available for a trademark.
๐ฅ๐ฒ๐๐ผ๐๐ฟ๐ฐ๐ฒ๐ An discussion: https://youtu.be/zMwXHT8JXAE?t=270 The papers shared: https://www.scotusblog.com/case-files/cases/united-states-patent-and-trademark-office-v-booking-com-b-v/ The oral arguments: https://www.c-span.org/video/?471417-1/supreme-court-oral-argument-patent-trademark-office-v-bookingcom