I don't know about IT policies, but I think any reasonably good IT org would just consider everyone's machine compromised -- owned by employer or employee both

I don't know about IT policies, but I think any reasonably good IT org would just consider everyone's machine compromised -- owned by employer or employee both and take security measures commiserate to the needs of the business. Regarding it being an investment - if you think anything can make you more productive and you can get the business to pay for it - sure, why not? Could be a chair or a desk or a coffee maker or a computer.