This rounds of the Banned and Restricted List update didn't affect Magic's most popular formats, but it did follow through on two formats that carry a following on Magic Online.

Pauper: Treasure Cruise is banned.

100 Card Singleton: Skullclamp is banned.

Both cards are already members of the banned list in other formats, so it's no surprise to see their power trickle down into more niche formats. To see the rationale (exactly the reasons you already suspect) you can read the official announcement.