You can. But once you manage to find a potential face on the screen that might fit, they aren’t advertising the fact that they’d consider a new opportunity. Extensive time and resources are needed to even make first contact as you are in competition with hundreds of others who are sending InMails, emails and using other means to attract them.
But if you do manage to attract them and ascertain they may be interested in a new opportunity, then it’s up to you to screen them, understand their deeper desires (like salary, geographical range, the type of company they hope to retire at, etc.) and learn even more about them on a personal level to understand if they are even worth interviewing.
Meanwhile, IT Pros has already done all of this. Our candidates are curated, screened and ready to step up to the plate now.