If internet is an "ordinary and necessary expense" for your Sch C "sole proprietorship" business.
Using the internet in your business as well as web-based advertising expenses may be deductible for your business depending on the business. Please refer to IRS Pubs 535 and 334.
You cannot deduct internet use for a W-2 job because the job expenses for a W-2 job are no longer deductible.
If you use a portion of your internet cost for your business and keep records documenting the amount that is used for your business, vs other uses, you should be able to deduct a portion of your internet cost for a business expense.
