I don't know the specifics behind why the communities were (re-)removed but the reasons given in the modlog seem vague enough to apply to anyone linking to Google or YouTube as they reference or indirectly link to piracy:

Removed Community CrackWatch@lemmy.dbzer0.com
reason: facilitating piracy, referencing websites used for the distribution of copyright infringing material in images

Removed Community Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ@lemmy.dbzer0.com
reason: facilitating piracy, indirectly linking to websites used for the distribution of copyright infringing material

From the initial removal announcement post:

The discussions that have happened in various threads on Lemmy make it very clear that removing the communites before we announced our intent to remove them is not the level of transparency the community expects, and that as stewards of this community we need to be extremely transparent before we do this again in the future as well as make sure that we get feedback around what the planned changes are, because lemmy.world is yours as much as it is ours.

EDITED multiple times due to confusion over origins of the ban.