I give up on 'viruses' (correctly: 'viri'). But I'm still going to fight the good fight on “data is” and “indexes”.
“Data” is the plural of “datum”. Data are, datum is. Shame on Microsoft! 2073A Coursebook, Module 6, page 8:
Data is physically stored on a data page in ascending order
No, data are stored.
And, despite how the system tables (e.g., sysindexes) are named, and what they say on page 11 of module 6, the proper plural of “index” is “indices”.