Norton cleans my portable apps USB stick

I am already for years a user of the set of tools created by (for example) Nirsoft. As well as Norton tools...

Yesterday I all of a sudden noticed that the USB stick used for these programs was cleaned (by Norton I assume). All portable apps gone, the Sysinternal suite, the Nirsoft tools.

Re-install of the portable apps suite succeeded, but when downloading the Nirsoft http://launcher.nirsoft.net/ suite I got a Symentec message: unsafe programs. I know for sure: no way this is correct! I managed to download the set by asking for the encrypted version of the Zip. Then I wanted to report an incorrect detection. Impossible to report!

questions:

- why did Symantec clean my USB stick? Only empty folders were left over? Even Sysinternals from Microsoft was removed?

- is this suite so dangorous that Norton does not allow me to download it?

- how do I forbid Norton to empty my USB stick again?

- how can I report this incorrect behaviour?

André